Spray a 9×9-inch pan with non-stick spray and line it with a foil or parchment paper sling.  Spray again.

Place a large pot on the stove over medium heat, add your butter and let it melt and then brown. *See notes below for browning butter.

5 Tablespoons Butter

Once the butter is browned, remove from the heat and add the salt and 8 cups of mini marshmallows. Stir until everything is completely melted and smooth. If you need to put it back on the heat to finish melting the marshmallows, that is fine. You just don’t want the browned butter to burn.

1/2 teaspoon Sea Salt,10 Cups Mini Marshmallows

Once it is smooth, add vanilla and stir again.

1/4 teaspoon Vanilla Extract

Measure out the rice krispies cereal in a large bowl. Pour the melted marshmallows over the rice krispies and mix well.  

6 Cups Rice Krispies Cereal

Add in the remaining marshmallows while still warm.

10 Cups Mini Marshmallows

Lightly press about half of the rice krispies mixture into your prepared pan (see note). Flatten it down so it is even in the pan and then spread the dulce de leche all over the rice krispies in an even layer.

1/2 Can Dulce de Leche

Top with the rest of the rice krispies mixture and lightly press it around until it is evenly spread into the pan. Let it set at room temperature until cooled.