For the homemade Oreo cookie butter:
30 Double Stuf Oreos
1/4 cup heavy whipping cream
For the sandwich:
2 slices white bread
1 tablespoon butter, room temperature
2 tablespoons mascarpone cheese
4 tablespoons Oreo cookie butter
2 Oreo cookies, crushed
4 tablespoons marshmallow fluff
To make the homemade cookie butter: Add cookies into a food processor and pulse until combined. Add cream and process for about 3 minutes until nice and smooth. Store in the refrigerator.
Heat up a skillet or griddle to medium heat. Butter one side of both slices of bread. On the other side of one slice of bread, spread a layer of mascarpone cheese followed by a layer of Oreo Cookie Butter. Sprinkle crushed Oreos on top. On the other slice of bread, spread a layer of marshmallow fluff. Carefully sandwich the two slices together so the chocolate and marshmallow fluff meet in the middle.
Place the sandwich on the heated skillet and cook until the bread is toasted and golden brown, about 2 minutes. Flip the sandwich and grill for an additional 2 minutes. Remove, cut and enjoy!