Preheat the oven to 350ºF. Lightly grease a 9-inch round cake pan. Set aside.

Melt 4 tablespoons of butter in a small pot over medium heat. Once melted, add ½ cup of light brown sugar. Stir to combine. Cook over medium heat for 3 minutes, stirring occasionally, until the sugar dissolves and the mixture darkens slightly in color.

Turn the heat to low and add 2 tablespoons heavy cream and 1 teaspoon vanilla extract. Whisk until smooth and simmer for 1 minute. Turn off the heat.

Pour the mixture into the prepared cake pan and smooth it into an even layer. Transfer to the refrigerator for 15 minutes.

Add the drained cherries to a bowl with 1 tablespoon cornstarch and 1 tablespoon amaretto liqueur. Stir to coat and set aside.

Use a sharp knife to finely chop the chocolate. It should be very finely shaved into shards of varying sizes. You can also use a grater or vegetable peeler to grate or shave it, if preferred.

Sift ¾ cup of all-purpose flour, 1 tablespoon powdered buttermilk, 1 teaspoon baking powder, and ¼ teaspoon kosher salt into a small bowl. Set aside.

Add 4 tablespoons of room temperature butter and ½ cup of granulated sugar to a large bowl. Use an electric hand mixer to cream them together. Add 2 eggs and beat until smooth.

Add half the sifted dry ingredients and beat with the mixer until just combined. Add half the milk and beat until just combined. Add the remaining dry ingredients and the remaining milk, along with 1 teaspoon of vanilla extract. Beat until just combined. Don’t over-mix! Gently fold in the chopped chocolate and set aside.

Remove the cake pan from the refrigerator. Pour the cherries on top of the caramel layer and arrange them in an even layer. Pour the batter over the cherries and smooth it out with the back of your spatula.

Transfer the cake to the oven and bake for 45 to 50 minutes until a toothpick inserted into the center of the cake comes out clean.

Let the cake stand at room temperature for 45 minutes. The cake should still be warm to the touch.

Place 1 cup heavy cream in a large bowl. Add ½ cup sifted powdered sugar and 6 tablespoons of the reserved maraschino liquid. Beat on medium-high speed until soft peaks form. Add the mascarpone and continue beating just until stiff peaks form, being careful not to overmix it. Cover and refrigerate up to 12 hours.

Place a large plate over the cake pan and carefully invert the cake onto the plate. Let stand for 1 hour until completely cool.

Transfer the frosting to a piping bag and frost the top of the upside-down cake, or use a rubber spatula to pile the frosting on top and smooth it out. Garnish with stem-on maraschino cherries and more shaved dark chocolate. Slice the cake and enjoy!