Preheat your oven to 350°F (175°C). Grease your 9x13-inch baking pan with non-stick cooking spray.
In a mixing bowl, combine the graham cracker crumbs and melted butter. Mix until the crumbs are evenly coated. Press into the bottom of the prepared pan to form a crust.
Dollop the Reese's Chocolate And Peanut Butter Spread over the crust. Spread it evenly across the crust with a spatula.
Pour the sweetened condensed milk evenly over the peanut butter layer.
Sprinkle the chocolate chips, Reese's Pieces, and flaked coconut over the condensed milk layer. Add optional ingredients if desired.
Bake for about 25-30 minutes, or until the edges are golden brown and the center is set.
Allow to cool in the pan for 10-15 minutes, then cut into squares and serve warm or at room temperature.
