Chocolate Pop Tarts with Peanut Butter and Jam Filling

Name: Chocolate Pop Tarts with Peanut Butter and Jam Filling
Ingredients: 1 cup (130 g) all-purpose flour; 1 cup (130 g) cake flour; 2 tablespoons unsweetened dark cocoa powder; 2 tablespoons granulated sugar; 1 1/2 teaspoons kosher salt; 1 large egg; 1 tablespoon whole milk; 1 tablespoon heavy cream; 1 tablespoon pure vanilla extract; 8 ounces (2 sticks/225 g) frozen unsalted butter, cut into 1/2-inch (12-mm) cubes; 3/4 cup (195 g) creamy peanut butter (see Notes); 4 ounces (115 g) dark chocolate, coarsely chopped; 1/2 cup (120 ml) heavy cream; 1/2 teaspoon pure vanilla extract; 1 1/2 to 2 cups (480 to 640 g) strawberry jam or preserves; 2 to 2 1/2 cups (225 to 280 g) confectioners' sugar; 1/4 cup plus 1 tablespoon (25 g) unsweetened dark cocoa powder; 1/4 cup plus 2 tablespoons (90 ml) whole milk; 2 teaspoons pure vanilla extract; 2 ounces (1/2 stick/55 g) unsalted butter, softened, cut into cubes; White, yellow, and orange sprinkles (optional)