Preheat oven and bake cookies according to package or recipe directions on parchment-lined baking sheets. Set aside to cool completely.

Beat softened butter and Nutella together with a hand mixer on medium-high until smooth and creamy.

Mix in powdered sugar one cup at a time on low speed until fully combined.

Add heavy cream and beat on medium-high for 2 to 3 minutes until frosting is light and fluffy. Refrigerate until ready to use.

Crush Oreos into fine crumbs using a blender, food processor, or a zip-top bag and rolling pin.

Spread or pipe Nutella frosting onto each cooled cookie.

Sprinkle about one tablespoon of Oreo crumbs over the frosting on each cookie.

Press one gummy worm into the top of each cookie. Serve right away or refrigerate until ready to enjoy.