Rice Krispies Treats with Chocolate and Pretzel

Ingredients
(makes 12-24 treats)

6 tablespoons salted butter (3/4 stick)
1 (10-ounce) bag marshmallows
3 cups Rice Krispies, or other crisp rice cereal
3 cups mini-pretzels, broken into 1/2- to 1-inch pieces
3 ounces semisweet chips or dark chocolate, chopped

1. Grease a 9-inch square baking pan with butter stick before melting to use in recipe.
2. Melt the butter in a large saucepan over medium-low heat. Add the marshmallows and stir with a spatula (silicone sticks less than wood here) until smooth and melted, about 3 minutes.
3. Remove from the heat, add the cereal and pretzels, and stir until evenly coated. Immediately scrape the mixture into the prepared pan. Using the spatula, press the mixture to evenly cover the bottom of the pan. Working quickly (you want the cereal mixture to still be quite warm so the chocolate will melt a bit and stick to the the surface), sprinkle the chopped chocolate on top. Press the mixture with the chocolate into a flat, even layer in the pan.
4. Cool to room temperature in the pan on a rack. Cut into squares. Serve immediately or transfer to an airtight container.