For the Chocolate Filling:
- 12 ounces semi-sweet chocolate, coarsely chopped
- 1 1/2 sticks (3/4 cup) unsalted butter
- pinch of salt
- 1/4 teaspoon ground cinnamon
- 2 tablespoons honey
- 1 1/2 cups finely ground chocolate wafer cookies (I sure did use Oreos without the cream)
For the Cake:
- 1 cup (2 sticks) unsalted butter, room temperature, plus more for pan
- 4 cups all-purpose flour, plus more for pan
- 2 teaspoons baking powder
- 2 teaspoons baking soda
- ½ teaspoon kosher salt
- 2 cups granulated sugar
- 4 large eggs
- 2 cups sour cream
- 2 teaspoons vanilla extract
- First make the chocolate filling, in a heatproof bowl over a double boiler, melt together the two chocolates and butter. Stir until smooth and glossy. Remove from the heat and stir in the salt, cinnamon and honey.
- Let the chocolate cool to room temperature. This step is important. We’ll need the chocolate at room temperature before we add the cookie crumbs so the mixture finished is thick and spreadable. Give the chocolate about 20 minutes to come to cool to room temperature.
- Stir in the chocolate cookies which should make the chocolate mixture thick but still spreadable.
- To make the cake, first place a rack in the center of the oven and preheat oven to 350° F. Butter and flour a Bundt pan or tube pan, tapping out excess flour.
- In a medium bowl, whisk together 4 cups flour, baking powder, baking soda, and salt in a medium bowl.
- In the bow of an electric stand mixer fitted with a paddle attachment lightly beat the softened butter.
- Add the sugar and beat on medium speed until light and fluffy, about 5 minutes. Add eggs one at a time, beating for 1 minute between each addition, scraping down sides of bowl after each addition.
- Beat in the vanilla extract.
- Reduce speed to low and add dry ingredients in 2 additions, alternating with sour cream.
- Scoop about 1 1/2 cups of batter into the prepared pan and smooth the surface. Spoon in about 1/3 cup of the chocolate filling and spread as best you can to smooth the surface. Repeat the layers until all of the batter and filling are gone but be sure to end with a layer of cake batter at the top of the pan.
- Smooth the surface and use a butterknife to gently swirl the layers together – about 8 swirls will do.
- Bake cake until golden brown and a tester inserted into the center comes out clean, 70–80 minutes. Transfer pan to a wire rack and let cake cool in pan 30 minutes before inverting onto wire rack. Let cool completely.
- Slice generously and dust with powdered sugar before serving.
- Cake will keep well wrapped at room temperature for up to 5 days.