Preheat your oven to 350°F (175°C) and grease a 9-inch round cake pan with butter. In a medium saucepan over low heat, melt 4 tablespoons of unsalted butter. Add ½ cup of granulated sugar, stirring until dissolved, then mix in your pitted cherries and 1½ teaspoons of vanilla extract, allowing to simmer until syrupy, about 5 minutes.

In a large mixing bowl, whisk together 1½ cups of all-purpose flour, ½ cup of unsweetened cocoa powder, 1½ teaspoons of baking powder, ½ teaspoon of baking soda, and ¼ teaspoon of salt. In another bowl, combine 2 large eggs, 1 cup of buttermilk, ½ cup of vegetable oil, and 1½ teaspoons of vanilla extract. Mix the wet ingredients into the dry until just combined, then stir in 1 cup of boiling water for a thin batter.

Carefully pour the cherry mixture into the prepared cake pan, spreading it evenly. Gently pour the chocolate cake batter over the cherries, ensuring an even layer. Bake for 35-40 minutes, or until a toothpick inserted in the center comes out clean.

Allow the cake to cool in the pan for about 10 minutes, then carefully invert it onto a serving platter so the cherry topping is on top. Serve warm or at room temperature.