Put the American Heritage chocolate and butter in a microwave safe bowl and microwave until melted, stirring every 30 seconds.
2 oz American Heritage Chocolate, 4 Tablespoon butter
Let the chocolate mixture cool for 10 minutes.
Preheat the oven to 350 F.
Stir in the eggs, vanilla and sugar until the mixture is well combined.
2 eggs, 1 teaspoon vanilla, 1/2 cup sugar
Sprinkle the flour, baking powder and salt on top and fold together until just mixed.
1/2 cup flour, 1 teaspoon baking powder, pinch salt
Pour the batter into a 5" cast iron skillet.
Microwave the peanut butter for about 30 seconds to melt it. Then pour it on top of the chocolate batter. Use a knife to swirl the peanut butter into the batter.