Preheat the oven to 425°F.
Spray each ramekin with nonstick spray/olive oil. Mix 1 tablespoon of flour with the cocoa powder. Coat the inside of each ramekin with this flour mixture and tap off the excess.
1 tablespoon unsweetened cocoa powder, 5 tablespoons all-purpose flour
In a medium saucepan, melt 1 stick (8 tablespoons) of butter with the German chocolate over very low heat, stirring occasionally. Once it is melted and mixed completely, take it off the heat and allow to cool for a couple minutes.
9 tablespoons unsalted butter, 6 ounces German baking chocolate
In a medium bowl, using a hand mixer, blend the peanut butter with the powdered sugar and the remaining 1 tablespoon of butter. Set aside.
3 tablespoons creamy peanut butter, 1 tablespoon powdered sugar
In another bowl, use a hand mixer to beat the granulated sugar with the eggs and salt at medium-high speed until thick and pale yellow, around 3 minutes. Turn off the mixer and fold in the chocolate, using a spatula. Blend until no streaks remain. Fold in the remaining flour and salt, and mix until smooth.
½ cup granulated sugar, 3 large eggs, 1 pinch kosher salt
Spoon two-thirds of the batter into the prepared ramekins, then place a large spoonful of the peanut butter mixture into the middle. Top with more chocolate batter. Leave about 2 centimeters at the top of the ramekin to allow for the cake to rise.
Bake for 14-16 minutes, or until the top is crispy/cracked and the middle is still slightly jiggly. Take out of the oven and allow to cool for about 10 minutes.
Run the tip of a thin knife around each cake to loosen. Invert a small plate over each cake and using pot holders, invert again. Carefully lift the ramekins off the hot cakes.
Dust the warm cakes with powdered sugar and serve right away. These are also great with vanilla ice cream!