Line a 9x13-inch baking dish with foil and lightly grease it so the treats come out easily later.

In a large pot over medium heat, melt the butter. Stir in the salt and vanilla for that perfect sweet-salty balance.

Add the marshmallows and stir constantly until they’re completely melted and smooth — about 5 to 7 minutes.

Remove from heat and gently fold in the Rice Krispies cereal until every bit is coated in that glossy marshmallow mixture.

Transfer the mixture into the prepared pan and let it cool for a minute or two so it’s easier to handle.

With greased hands or a rubber spatula, press the mixture into an even layer — not too firm, just enough to hold its shape.

Let it sit at room temperature for about 30 minutes, until firm and set.

Once cooled, lift it out of the pan and place it on a cutting board.

Melt the white chocolate in the microwave in 30-second bursts, stirring between each until smooth. Drizzle it over the top, then add sprinkles and M&Ms for that festive pop of color.

Finish with another quick drizzle of white chocolate and a few more sprinkles if you’re feeling extra festive.

Let the chocolate harden completely, then cut into squares and serve.