Coat a 9x9 baking pan with non-stick cooking spray and set aside.

In a medium-sized bowl, combine the butter, crumbs, sugar and peanut butter and stir to combine. You can also mix in a food processor to ensure that everything is extra smooth.

Press peanut butter mixture into the casserole pan until it forms an even layer.

Place the white chocolate chips and coconut oil in a microwave-safe bowl and heat in 25 second increments. Stir in between each heating until fully melted.

Pour the melted white chocolate into baking dish over the peanut butter layer and smooth out with an offset spatula.

Melt the dark chocolate, using the same method as above, and drizzle over the white chocolate.

Use your offset spatula to run parallel lines through the chocolate to create a pretty pattern.

Place in the refrigerator to set for at least 2 hours.