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My mother started her coconut cake on a Thursday for a Sunday, and if you asked her whether that was really necessary, she would cut you a slice of somebody else’s and let you answer for yourself.
Most coconut cakes are dry, and the reason is that people bake the layers and frost them the same day. Hers were baked, split, and every layer was spread with a mixture of sour cream, sugar and coconut. Then the cake went into the refrigerator under a cake cover and stayed there for three days. Three. The layers drank the coconut and sour cream until they were more pudding than cake.
The frosting went on last, on the third day, and it was not buttercream. It was the old cooked kind, egg whites and sugar beaten over a pan of boiling water for seven minutes until it stood up in glossy peaks like marshmallow. It does not keep well, which is why it went on last.
Why this three-day coconut cake works
- Layers split thin. Four thin layers mean three seams of filling instead of one, so the sour cream soaks the whole cake.
- Sour cream, sugar and coconut. The sugar draws moisture out of both, and over three days it all moves into the cake.
- Three days in the refrigerator. One day is good. Three is the cake people remember, soft all the way through.
- A cooked white frosting, put on last. Egg whites and sugar beaten over boiling water set into a light, glossy marshmallow frosting that suits a soaked cake better than buttercream.
Ingredients
Makes one 9 inch four-layer cake, 16 slices. Start it three days ahead. The measurements are in US cups with grams in brackets.
For the layers
- 2 1/2 cups cake flour (285g)
- 2 1/2 teaspoons baking powder
- 1/2 teaspoon fine salt
- 1 cup unsalted butter (2 sticks, 226g), softened
- 1 3/4 cups granulated sugar (350g)
- 4 large eggs
- 1 cup whole milk (240ml)
- 2 teaspoons vanilla extract
- Butter and flour for the pans
For the filling
- 2 cups sour cream (480g)
- 1 1/2 cups granulated sugar (300g)
- 2 cups sweetened flaked coconut (170g)
For the frosting and the outside
- 2 large egg whites
- 1 1/2 cups granulated sugar (300g)
- 1/3 cup cold water (80ml)
- 1 tablespoon light corn syrup
- 1/4 teaspoon cream of tartar
- A pinch of salt
- 1 teaspoon vanilla extract
- 2 cups sweetened flaked coconut (170g), for covering the cake
Sweetened flaked coconut is right for both the filling and the outside. Many of our mothers baked the layers from one box of white or yellow cake mix in two 9 inch pans, and the cake is just as good that way.
How to make three-day coconut cake
Day one: the layers and the filling
- Stir the filling first: mix the sour cream, sugar and 2 cups of coconut in a bowl, cover and refrigerate while you bake. It thickens as the sugar dissolves.
- Heat the oven to 350°F (175°C). Butter two 9 inch round cake pans, line the bottoms with parchment and dust with flour.
- Whisk the flour, baking powder and salt together. Beat the butter and sugar on medium for 3 to 4 minutes, until pale and fluffy. Add the eggs one at a time. Stir the vanilla into the milk.
- On low speed, add the flour in three parts and the milk in two, beginning and ending with flour, mixing only until each addition disappears. Divide the batter between the pans.
- Bake at 350°F for 25 to 30 minutes, until the tops spring back and a toothpick comes out clean. Cool in the pans 10 minutes, then turn out onto racks and cool completely.
- Split each cooled layer in half horizontally with a long serrated knife so you have four thin layers. Put the first layer cut side up on the serving plate and spread it with a third of the filling, right to the edges. Repeat with the second and third layers, then set the top layer on cut side down and leave the top and sides bare.
- Cover the cake with a cake cover or an upturned bowl and refrigerate for three days. Do not cut it and do not frost it.
Day three: the frosting
- A few hours before serving, bring 2 inches of water to a boil in a saucepan. In a heatproof bowl that sits on the pan without touching the water, combine the egg whites, sugar, cold water, corn syrup, cream of tartar and salt.
- Set the bowl over the boiling water and beat with a hand mixer on high for 7 minutes by the clock, until the frosting is thick, glossy white and stands in stiff peaks. Take it off the heat, add the vanilla and beat 1 minute more.
- Take the cake out of the refrigerator and, working fast, spread the frosting thickly over the top and sides in soft swoops. Press the remaining 2 cups of coconut all over it with your palm.
- Refrigerate for at least 1 hour so the frosting firms, then slice with a long thin knife wiped between cuts.
Tips that make the difference
- Mark the middle of each layer with toothpicks before splitting and rest the knife on them.
- Spread the filling all the way to the edges. The edges are where a cake dries out first.
- Beat the frosting the full 7 minutes over water that is truly boiling. Under-beaten frosting slides off a cold cake.
- Frost on serving day. This frosting is at its best for about 24 hours.
Variations
- Three layers. Divide the batter among three 8 inch pans, bake 22 to 25 minutes, and do not split them, for the tall three-layer look. Give it the same three days.
- Pineapple. Stir 1/2 cup well drained crushed pineapple (120g) into the filling.
- Coconut milk in the batter. Use canned coconut milk in place of the whole milk in the layers.
- Sour cream all over. Skip the cooked frosting, make half again as much filling, and cover the whole cake with it before the three days. Denser, and even damper.
Storage and make-ahead
The filled, unfrosted cake keeps in the refrigerator, covered, for up to 5 days. Once frosted, eat it within 2 days.
Always store this cake cold. The sour cream filling has to be refrigerated.
Slices of the filled, unfrosted cake freeze well for up to 2 months. The frosted cake does not freeze.
Frequently asked questions
Do I really have to wait three days?
One day makes a good cake. Three days makes the cake people remember, because the sour cream and coconut keep moving into the layers the whole time.
Is the sour cream filling safe to leave for three days?
Yes, in the refrigerator, covered. Sour cream, sugar and coconut all keep well cold, and the filled cake stays good for up to 5 days.
Can I use buttercream instead of the cooked frosting?
You can, but the cake is heavier for it. The cooked frosting is light and marshmallow soft, which suits a soaked cake.
Why did my frosting go grainy or slide off?
Grainy means the sugar was not dissolved: keep beating over boiling water until smooth and stiff. Sliding means it was under-beaten or the cake surface was wet; pat the top dry before frosting.
Bake it, split it, fill it, and then do the hardest part, which is leaving it alone for three days. On Sunday, beat the frosting, roll it in coconut, and cut the first slice for whoever asked whether it was necessary.
Three-Day Coconut Cake (Sour Cream Filling and Cooked White Frosting)
The Southern three-day coconut cake: two 9 inch layers split into four, filled with sour cream, sugar and sweetened coconut, refrigerated three days, then covered in a fluffy cooked white frosting beaten seven minutes over boiling water and rolled in coconut.
Ingredients
- 2 1/2 cups cake flour
- 2 1/2 teaspoons baking powder
- 1/2 teaspoon fine salt
- 1 cup unsalted butter (2 sticks, 226g), softened
- 1 3/4 cups granulated sugar
- 4 large eggs
- 1 cup whole milk
- 2 teaspoons vanilla extract
- Butter and flour for the pans
- 2 cups sour cream
- 1 1/2 cups granulated sugar
- 2 cups sweetened flaked coconut
- 2 large egg whites
- 1 1/2 cups granulated sugar
- 1/3 cup cold water
- 1 tablespoon light corn syrup
- 1/4 teaspoon cream of tartar
- A pinch of salt
- 1 teaspoon vanilla extract
- 2 cups sweetened flaked coconut (170g), for covering the cake
Instructions
- Stir the filling first: mix the sour cream, sugar and 2 cups of coconut in a bowl, cover and refrigerate while you bake. It thickens as the sugar dissolves.
- Heat the oven to 350°F (175°C). Butter two 9 inch round cake pans, line the bottoms with parchment and dust with flour.
- Whisk the flour, baking powder and salt together. Beat the butter and sugar on medium for 3 to 4 minutes, until pale and fluffy. Add the eggs one at a time. Stir the vanilla into the milk.
- On low speed, add the flour in three parts and the milk in two, beginning and ending with flour, mixing only until each addition disappears. Divide the batter between the pans.
- Bake at 350°F for 25 to 30 minutes, until the tops spring back and a toothpick comes out clean. Cool in the pans 10 minutes, then turn out onto racks and cool completely.
- Split each cooled layer in half horizontally with a long serrated knife so you have four thin layers. Put the first layer cut side up on the serving plate and spread it with a third of the filling, right to the edges. Repeat with the second and third layers, then set the top layer on cut side down and leave the top and sides bare.
- Cover the cake with a cake cover or an upturned bowl and refrigerate for three days. Do not cut it and do not frost it.
- A few hours before serving, bring 2 inches of water to a boil in a saucepan. In a heatproof bowl that sits on the pan without touching the water, combine the egg whites, sugar, cold water, corn syrup, cream of tartar and salt.
- Set the bowl over the boiling water and beat with a hand mixer on high for 7 minutes by the clock, until the frosting is thick, glossy white and stands in stiff peaks. Take it off the heat, add the vanilla and beat 1 minute more.
- Take the cake out of the refrigerator and, working fast, spread the frosting thickly over the top and sides in soft swoops. Press the remaining 2 cups of coconut all over it with your palm.
- Refrigerate for at least 1 hour so the frosting firms, then slice with a long thin knife wiped between cuts.
