For the chocolate cake layer:

  1. Preheat the oven to 350, and position a rack in the lower third of the oven.
  2. Line a 6″ round cake pan (with 2″ sides) with parchment paper on the bottom, and lightly grease the sides with oil.
  3. Next, in a medium bowl, whisk together the flour, cocoa powder, and baking soda. Set aside.
  4. In a small bowl, whisk together the oil, sugar, sour cream, egg, vanilla and coffee.
  5. Combine the two bowls, mixing just until combined.
  6. Pour the batter into the cake pan, and bake for 29-32 minutes, or until a toothpick inserted into the cake comes out clean. If you under-bake the cake, it will slightly sink, so check it! It will also start to pull away from the sides when it’s done.
  7. Remove the cake from the pan by carefully tilting it into one hand, peel off the parchment from the bottom, and then place it on a small cake stand.

For the strawberry cake layer:

  1. Place the freeze-dried strawberries in a mini food processor, and pulverize to a fine powder. You will get about 1/4 cup of strawberry powder.
  2. Preheat the oven to 350, and spray a 6″ round cake pan with 2″ sides with cooking spray. Line the bottom of the pan with a round of parchment paper.
  3. In a medium-size bowl, beat together the butter and sugar with an electric mixer. Beat very well, about 1-2 minutes.
  4. Add the egg and vanilla, and beat until well-combined, about 15 seconds.
  5. In a small bowl, whisk together the flour, salt and baking soda. Add half of the this to the batter and beat for just a few seconds before stirring in half of the buttermilk. Continue beating. Add the remaining dry ingredients and beat, and then stir in the remaining buttermilk. Finally, beat in the strawberry powder and red food coloring (if using).
  6. Scrape the batter into the prepared pan, smooth out the top, and bake on a small sheet pan for 37-39 minutes, until a cake tester comes out clean.
  7. Let the cake cool on a wire rack in the pan. Carefully remove it from the pan, pulling away the parchment paper once it has cooled.

For the vanilla cake layer:

  1. Preheat the oven to 350, and spray a 6″ round cake pan with 2″ sides with cooking spray. Line the bottom of the pan with a round of parchment paper.
  2. In a medium-size bowl, beat together the butter and sugar with an electric mixer. Beat very well, about 1-2 minutes.
  3. Add the egg and vanilla, and beat until well-combined, about 15 seconds.
  4. In a small bowl, whisk together the flour, salt and baking soda. Add half of the this to the batter and beat for just a few seconds before stirring in half of the buttermilk. Continue beating. Add the remaining dry ingredients and beat, and then stir in the remaining buttermilk. Finally, beat in the strawberry powder and red food coloring (if using).
  5. Scrape the batter into the prepared pan, smooth out the top, and bake on a small sheet pan for 37-39 minutes, until a cake tester comes out clean.
  6. Let the cake cool on a wire rack in the pan. Carefully remove it from the pan, pulling away the parchment paper once it has cooled.

To assemble the cake:

  1. To make the buttercream, beat the butter in a medium-size bowl with an electric mixer until light and fluffy. Add the powdered sugar, vanilla and heavy cream, and beat until light and fluffy. If the mixture seems too stiff, add a splash more heavy cream.
  2. Place the chocolate cake layer on a small cake stand. Top with about 1/3 cup of the frosting and spread almost to the edges.
  3. Add the strawberry layer on top, and repeat with the frosting.
  4. Finally, add the vanilla cake layer on top and apply a thin crumb coat of buttercream. Chill the cake for at least one hour, up to 8 hours.
  5. Next, use about 80% of the rest of the buttercream to frost the cake. Combine the remaining buttercream with the jam and red food coloring (if using).
  6. Dollop the strawberry buttercream all over the cake, and then smooth it to blend with the vanilla buttercream.
  7. Slice and serve.