Ingredients
Scale
- 1/2 cup unsalted butter (melted (1 stick))
- 1 large egg
- 3/4 cup light brown sugar (packed)
- 1/4 cup granulated sugar
- 2 tablespoons brewed coffee (optional but highly recommended)
- 1 tablespoon vanilla extract
- 1 1/2 cups 6 3/8 oz. all-purpose flour
- 1/3 cup 1 oz. unsweetened natural cocoa powder
- 1/2 teaspoon baking soda
- 1/4 teaspoon kosher salt
- 1/2 bag (8 oz. Rolos Unwrapped Bites (or chopped Rolos))
- about 1/2 cup sweetened condensed milk (just about half of one standard 14-ounce can)
Instructions
- Preheat oven to 350F. Line an 8-by-8-inch baking pan with aluminum foil, spray with cooking spray; set aside.
- In a large microwave-safe bowl, melt the butter, about 1 minute. Allow the butter to cool for one minute. Add the egg, sugars, coffee (water may be substituted but coffee is recommended), vanilla, and stir or whisk vigorously to combine.
- Add the flour, cocoa powder, baking soda, salt and stir until just incorporated.
- Reserve about 2/3 cup dough; set aside. Turn remaining dough out into prepared pan, smoothing it lightly with a spatula. Evenly sprinkle the Rolo bites over the dough. Pour sweetened condensed milk over the top (just eyeball slightly over half of the can as you pour slowly). Using your fingers, lightly crumble the reserved cookie dough over the top in irregular, marble-sized chunks.
- Bake for about 27 to 30 minutes, or until center is mostly set. The sweetened condensed milk should nearly be set in all places, but possibly a little loose in the very center of the pan is okay. Bars firm up more in pan as they cool; don’t overbake because you want these to stay soft and gooey.
- Allow bars to cool in pan for at least 3 hours before slicing and serving for the cleanest cut marks (use foil overhang to lift out). Extra bars will keep airtight at room temperature for up to 1 week, or in the freezer for up to 3 months.