In a bowl, mix the peanut butter, collagen powder, sweetner, butter and coconut flour until combined.
Line a baking sheet with greaseproof or baking parchment and spread the peanut butter mixture evenly on the sheet to about 1cm thickness.
Chill in the fridge for approximately 20-30 minutes until set.
To make the chocolate layer, melt the dark chocolate on a bain marie or in a microwave, contantly stirring to ensure the chocolate does not burn.
Once melted, add the butter to the chocolate and stir until the butter melts and the chocolate mixture is smooth and shiny.
Remove the peanut butter layer from the fridge and pour the liquid chocolate on top. Smooth out the chocolate with the back of a spoon to ensure the peanut butter layer is evenly covered.
Chill in the fridge for approximately an hour and a half, or until set.
Cut into 16 servings and enjoy.
