Preheat the oven to 350 degrees F. Lightly spray two 9-inch-round cake pans with non-stick cooking spray and dust with cocoa powder.
Whisk together the flour, baking powder, baking soda and salt in a medium bowl. Beat together the butter, granulated sugar, brown sugar and oil in a stand mixer fitted with the paddle attachment on medium speed until light and fluffy, about 2 minutes.
Meanwhile, whisk together the hot coffee, 3/4 cup cocoa powder and vanilla in a medium bowl until smooth.
Add the eggs to butter mixture one at a time, mixing well and scraping down the bowl between each addition. Beat in the coffee mixture until well combined. Add half of the flour mixture and beat just until combined, then beat in the sour cream followed by the remaining flour mixture. Scrape down the bowl and beat 1 minute more.
Divide the batter between the prepared cake pans. Bake until a toothpick inserted in the center comes out clean, 25 to 30 minutes. Transfer to racks. When the cakes are cool enough to handle, turn them out onto the racks to cool completely before frosting.
To assemble the cake, place one cake layer onto a serving platter or cake stand. Trim the top with a long serrated knife to make it level, if needed. Spread half of the Cherry Jam Filling on top in an even layer. Top with the other cake layer and frost the entire cake with chocolate frosting. Spread the remaining Cherry Jam Filling on top of the cake.
Cherry Jam Filling:
Yield:About 2 cups
Stir together 2 tablespoons water with the cornstarch in a small bowl until the cornstarch dissolves. Combine the cherries, sugar, remaining 6 tablespoons water and the lemon juice in a medium pot over medium heat and simmer for 2 minutes. Stir in the cornstarch mixture and continue to simmer, stirring occasionally, until the mixture has thickened and looks clear and shiny, about 5 minutes. Cool to room temperature and then refrigerate, covered, until cold, about 1 hour.