01 -
Preheat your oven to 350°F (175°C). Grease and flour a 9-inch round cake pan that's at least 2 inches deep, or an 8x8 inch square baking dish. Line the bottom with a round of parchment paper for easy removal later.
02 -
In a small bowl, mix together the ⅓ cup sugar and 1 teaspoon cornstarch until well combined. If using frozen cherries, allow them to thaw for about 20 minutes first. Toss the pitted cherries with the sugar-cornstarch mixture until evenly coated.
03 -
Spread the coated cherries evenly across the bottom of your prepared pan. They will release their juices during baking to create a glossy, sweet topping once the cake is inverted.
04 -
In a large mixing bowl, combine all the cake batter ingredients: sugar, flour, cocoa powder, baking powder, baking soda, salt, eggs, soured milk, brewed coffee, vegetable oil, and vanilla extract. Using an electric mixer, beat everything together on medium speed for 2 minutes until smooth and well combined.
05 -
Carefully pour the chocolate cake batter over the cherry layer, taking care to pour slowly and evenly to avoid disturbing the cherries too much.
06 -
Place the cake in your preheated oven and bake for 30-35 minutes. The cake is done when a toothpick inserted into the center comes out clean or with just a few moist crumbs attached.
07 -
Allow the cake to cool in the pan for exactly 5 minutes - this timing is important. If you flip too soon, the cake may fall apart, but waiting too long might cause it to stick. After 5 minutes, place a heat-proof serving plate upside down over the cake pan, then carefully flip everything over in one quick motion. Gently lift off the cake pan and peel away the parchment paper if it's stuck to the cherries.
08 -
Serve the cake warm or at room temperature with a scoop of vanilla ice cream, a dollop of freshly whipped cream, or a drizzle of chocolate ganache if desired.