Prepare 4 6oz ramekins with shortening and sprinkle a little bit of flour or cocoa powder and move around bottom and up the sides of ramekins, this helps the cake from sticking to sides.
In medium bowl add your baking bar and butter and melt in microwave.
Whisk in your powdered sugar until combined.
Add in your eggs and egg yolks until blended.
Lastly add in your flour until mixed.
In small bowl stir together peanut butter and Butterfinger baking bits.
Fill each ramekin half way with batter.
Separate your peanut butter mixture out into 4 equal portions and spoon peanut butter into center of batter, pressing down slightly.
Top with remaining batter to cover.
Place ramekins on a baking sheet and bake for 13-15 minutes until outside is firm and center is a little jiggly still.
Remove from oven and let sit a few minutes before turning out onto a plate.
Top with ice cream, chocolate syrup and additional Butterfinger bits if desired.