Preheat the oven to 425 degrees F.
Spray each ramekin with cooking spray/olive oil. Mix 1 tablespoon flour with 1 tablespoon cocoa powder. Coat the inside of each ramekin with this flour mixture and tap off the excess.
In a medium saucepan, melt 1 stick 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.
In a medium bowl, blend the peanut butter with the 1 tablespoon of confectioners' sugar and the remaining 1 tablespoon of butter. (I used a hand blender with the mixer attachment and it worked great.) Set aside.
In another bowl, use an electric 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 flour and mix until smooth.
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!