Step 1

Grease two 9-inch round cake pans to ensure your cakes don’t stick and come out perfectly.

Step 2

In a medium bowl, whisk together the flour, baking soda, and salt. This step is crucial for even distribution of the leavening agents.

Step 3

In a large bowl, beat the softened butter and granulated sugar together until light and fluffy. This process incorporates air into the mixture, giving your cake a light texture.

Step 4

Make sure to beat well after each addition. This ensures that the eggs are fully incorporated, which is key for a smooth batter.

Step 5

Mix in the sour cream and vanilla extract to add moisture and depth of flavor to your cake.

Step 6

Stir in the mashed bananas until fully incorporated. The bananas add natural sweetness and moisture, making the cake tender and flavorful.

Step 7

Gradually add the dry ingredients to the wet mixture, mixing until just combined. Overmixing can make the cake dense, so be gentle.

Step 8

Fold in the chopped walnuts to distribute them evenly throughout the batter.

Step 9

Divide the batter evenly between the two prepared cake pans and smooth the tops with a spatula. Bake for 35-40 minutes, or until a toothpick inserted into the center comes out clean.

Step 10

Allow the cakes to cool completely in the pans. Once cooled, remove them from the pans and level the tops if necessary.

Step 11

Place one cake layer on a serving plate, spread a generous layer of vanilla custard on top, then add the second cake layer. Drizzle the remaining vanilla custard over the top of the cake.

Step 12

Top the cake with banana slices and additional walnuts before serving. This final touch not only adds flavor but also makes the cake look as good as it tastes.