Dry ingredients - Sift together flour, baking powder, baking soda, and salt, set aside.
In a bowl of a stand mixer with the paddle attachment, cream butter and sugar until light and fluffy.
Add eggs, one at a time. Followed by the vanilla extract.
Next, add the flour mixture and sour cream in three batches.
Divide the batter into two pans. One for the vanilla and one for the chocolate.Tip - I like to use two similar bowls and divide the batter using a scale so I have two equal portions.
Vanilla batter - Pour the vanilla batter into one prepared baking pan.
Chocolate batter - Add the melted and cooled chocolate to the second batter. Then pour into the second cake pan.
Bake for about 25 to 30 minutes until a skewer inserted in the center comes out clean.Tip - make sure to adjust the baking time if you use 4 pans instead of 2.
Cool in the pan for 10 minutes then invert on a cooling rack and cool completely. At least a few hours.
In a microwave-safe bowl, heat the chocolate and cream until melted and smooth.Tip - Alternatively you can heat the cream in a saucepan and pour over the chocolate. Stir until melted.
Let cool at room temperature overnight or a few hours in the fridge. You want the ganache to set to about peanut consistency.
Once cooled, use a bread knife to cut the domes off the cake layers. Cut each cake horizontally into 2. So you have flour layers.
Cut the circlesUsing a 6-inch cookie cutter, cut a circle into each 9-inch layer.Then, use a 3-inch cookie cutter and cut another circle out of the 6-inch layers. You should now have 4 x 9-inch rings, 4 x 6-inch rings, and 4-3 inch centers.
Arrange the circlesNow, place a 9-inch vanilla ring on a plate and insert a 6-inch chocolate ring inside it, followed by a 3-inch vanilla center. Then, take a 9-inch chocolate ring on a plate and insert a 6-inch vanilla ring inside it, followed by a 3-inch chocolate center. Now, do the same with the leftover rings until you have 4 similar cake layers.
The nutrition information and metric conversion are calculated automatically. I cannot guarantee its accuracy. If this data is important to you please verify with your trusted nutrition calculator. Thank you