Preheat your oven to 350°F (175°C). In a medium saucepan, melt 4 tablespoons of unsalted butter over medium heat. Stir in 1 cup of granulated sugar and cook until bubbly and slightly caramelized, about 2–3 minutes. Add 2 cups of tart cherries and 1 teaspoon of vanilla extract, mix well, and pour into your prepared cake pan to form the topping.

In a large bowl, sift together 1 ½ cups of all-purpose flour, ½ cup of unsweetened cocoa powder, 1 teaspoon of baking powder, ½ teaspoon of baking soda, and ½ teaspoon of salt. In another bowl, whisk together 2 large eggs, 1 cup of buttermilk, ½ cup of vegetable oil, and 1 teaspoon of vanilla extract until combined. Gradually add the wet mixture to the dry ingredients, stirring until just mixed; fold in 1 cup of boiling water carefully.

Gently pour the chocolate cake batter over the cherry topping in the pan, smoothing the batter to create an even surface. Place the pan in the oven and bake for 35–40 minutes, checking with a toothpick inserted in the center.

Allow the cake to cool in the pan for 10 minutes. Carefully invert onto a serving platter, revealing the caramelized cherry topping. Serve warm or at room temperature.