Prepare the base by mixing the graham cracker crumbs, cocoa powder, sugar, and melted butter.
Press the crumb mixture into the bottom of a lined 9x9 inch baking pan and smooth the top.
In a separate bowl, combine the peanut butter, powdered sugar, and vanilla extract until smooth.
Spread the peanut butter mixture evenly over the crust in the pan.
Melt the chocolate chips with coconut oil until smooth and pour over the peanut butter layer.
Allow the bars to chill in the refrigerator for at least 2 hours until set.
Once set, remove the bars from the pan and cut them into squares before serving.
