Sour Cream Coffee Cake

Before you start

This is the rich, fine-crumbed coffee cake of church bake sales and diner counters: a sour cream batter baked in a tube pan with a ribbon of cinnamon, brown sugar and walnuts through the center and more of the same, bound with butter, on top. Sour cream brings moisture and tang and helps keep the cake soft for days.

Layering is the decision that shapes the cake. A thin middle layer of filling creates a clean swirl; too much in one place makes a weak seam that splits when you slice. Use a tube pan with a removable bottom so you can lift the cake out with the streusel still facing up instead of flipping it.

Ingredients

• Cinnamon-nut mixture150 g (¾ cup packed) light brown sugar
• 1 tbsp ground cinnamon
• 85 g (¾ cup) walnuts — finely chopped
• 30 g (¼ cup) all-purpose flour — for the topping portion
• 45 g (3 tbsp) unsalted butter — melted, for the topping portion
• Cake340 g (2¾ cups, spooned and leveled) all-purpose flour
• 2 tsp baking powder
• 1 tsp baking soda
• ½ tsp fine salt
• 170 g (¾ cup) unsalted butter — softened
• 250 g (1¼ cups) granulated sugar
• 3 large eggs — room temperature
• 2 tsp vanilla extract
• 360 g (1½ cups) full-fat sour cream — room temperature

Method

1. Heat the oven to 180°C (350°F). Grease and flour the tube pan, including the center tube.
2. Mix the brown sugar, cinnamon and walnuts. Transfer half to a second bowl and stir in the 30 g flour and melted butter until crumbly; this is the topping. The other half stays loose for the middle.
3. Whisk the flour, baking powder, baking soda and salt.
4. Beat the butter and sugar on medium-high for 3 minutes, until light and fluffy. Add the eggs one at a time, beating well after each, then the vanilla.
5. On low speed, add the flour mixture in three parts alternately with the sour cream in two parts, starting and ending with flour. Stop as soon as no dry flour shows. The batter will be thick.
6. Spread half the batter in the pan. Sprinkle the loose cinnamon-nut mixture evenly over it, keeping it 1 cm from the sides. Dollop the rest of the batter over the top and spread it gently to cover. Scatter the buttery topping over the surface.
7. Bake for 50 to 60 minutes, until the cake is risen and golden under the streusel and a skewer in the thickest part comes out clean. An instant-read thermometer should read about 96°C (205°F).
8. Cool in the pan on a rack for 20 minutes. Run a thin knife around the sides and tube, lift the cake out by the center, then slide it off the base. Cool at least 40 minutes more before slicing.

Tips for success

• Room-temperature sour cream and eggs keep the batter smooth. Cold dairy can make the creamed butter seize and turn grainy.
• Dollop the top layer of batter in spoonfuls before spreading it so you do not drag the filling up into streaks.
• Slice with a serrated knife using a gentle sawing motion to keep the streusel on top.

Substitutions

Sour cream

Full-fat plain Greek yogurt works one for one. The cake is slightly tangier and a touch less rich.

Tube pan

Bake in a 23 x 33 cm (9 x 13 in) pan for 35 to 45 minutes, layering the same way. The cake is flatter with more topping per bite.

Walnuts

Pecans are an easy swap. For nut-free, replace them with an extra 30 g brown sugar and 30 g flour in the mixture.

Troubleshooting

Cake split along the filling layer

Too much loose filling formed a seam. Keep the middle layer thin and evenly scattered, and keep it away from the pan walls.

Topping sank into the cake

The batter was thin from overbeating or warm butter. Mix just until combined after adding flour.

Domed, cracked top and dry crumb

The oven ran hot or it baked too long. Check oven temperature and start testing at 50 minutes.

Storage

Wrap the cooled cake or cover it under a cake dome and keep at room temperature for up to 3 days. Slices freeze well for up to 3 months; thaw at room temperature.

Safety notes

Do not taste the raw batter, which has uncooked egg and flour. Contains wheat, egg, milk and tree nuts.