01 - Lightly grease a 9x13-inch baking pan or line it with parchment paper.
02 - In a large saucepan over medium-low heat, melt the unsalted butter. Add the mini marshmallows and stir constantly until fully melted and the mixture is smooth. Remove from heat and incorporate the vanilla extract.
03 - Quickly fold the prepared cereal into the marshmallow mixture, ensuring all pieces are evenly coated.
04 - Gently stir in half of the candy-coated chocolates and half of the mini chocolate chips to the mixture.
05 - Press the prepared mixture firmly and evenly into the baking pan, using a buttered spatula or wax paper for an even surface.
06 - Scatter the remaining candy-coated chocolates, remaining mini chocolate chips, and all of the candy eyes over the surface, pressing lightly to adhere.
07 - Allow the bars to cool completely at room temperature, approximately 30 minutes. Slice into 12 equal bars when fully set.