Step 1

Coat an 8x8x2-inch baking pan with cooking spray or softened butter. Line the pan with a parchment paper sling that hangs off two sides.

Step 2

Melt 1 stick salted butter in a large pot over medium heat. Add 1/3 cup sweetened condensed milk and 2 to 3 tablespoons liquor of choice. Stir with a flexible spatula until the mixture is combined and just starting to bubble, about 2 minutes.

Step 3

Add 10 ounces mini marshmallows, 1 teaspoon kosher salt, 1/2 teaspoon freshly grated nutmeg, and 1/4 teaspoon ground cinnamon, and stir until the marshmallows are melted. Add 1 teaspoon vanilla extract and stir to combine. Remove the pot from the heat.

Step 4

Add 6 cups puffed rice cereal and 1 cup mini marshmallows, if using, and stir until evenly coated. The extra cup of marshmallows is a little fussy, I know, but provides pockets of melted gooeyness throughout each treat.

Step 5

Transfer the mixture to the prepared pan. Cover with plastic wrap and press down lightly with your hands to evenly flatten the treats. Uncover and dust with more grated nutmeg. Let cool 1 to 2 hours.

Step 6

Grasping the excess parchment, remove the slab of treats from the pan and place on a cutting board. Cut into 16 squares.