Begin by preheating your oven to 350°F (175°C). Grease and flour two round cake pans. This step is crucial to ensure the cake releases easily after baking.

In a large mixing bowl, combine the butter and cream cheese until smooth. This process should take about 2-3 minutes. You want to create a fluffy texture that will add richness to the cake.

Next, beat in the eggs one at a time, mixing well after each addition. Then stir in the vanilla extract. The eggs contribute to the cake’s height and texture, so be thorough here.

In a separate bowl, combine the cake mix and sour cream. Gradually add this mixture to your wet batter using a spatula. Fold gently until just combined. This will prevent overmixing, which could lead to a tough cake.

Pour the batter evenly into the prepared cake pans. Bake in the preheated oven for 25-30 minutes or until a toothpick inserted into the center comes out clean.

Once baked, remove the cakes from the oven and let them cool in the pans for about 10 minutes. After that, transfer them to a wire rack to cool completely.

Once cooled, frost the top of one cake layer with your choice of frosting (traditional cream cheese frosting works wonders). Place the second layer on top and frost the sides and top of the cake generously.