Melt ½ cup of salted butter in a large pot over medium-low heat. Stir in ½ cup of unsweetened cocoa powder and 1 tablespoon of espresso powder for 3–5 minutes until smooth.

Whisk in one 14-ounce can of sweetened condensed milk, heating for an additional 2 minutes while stirring continuously until thicker and creamier.

Add 10 unwrapped soft caramels and stir for 4–5 minutes until melted completely into the chocolate base.

Stir in 2 cups of mini marshmallows over low heat for 2–3 minutes until well combined and melty.

Remove from heat and add 1 teaspoon of vanilla extract, stirring until fully incorporated.

Fold in 4 cups of Rice Krispy cereal gently to avoid crushing them.

Line two 9x9 inch baking pans with parchment paper and scoop the mixture, flattening it slightly to form bars.

Refrigerate for 30 minutes to 1 hour until firm to the touch.

Cut into squares or rectangles, serve or store in an airtight container.