Preheat the oven to 350F. Line a 9x13 baking pan with tin foil. Grease with cooking spray and set aside.
Make the Brownies:
Place the chocolate chips and butter in a medium-sized microwave safe bowl. Microwave on 50% power for 2-3 minutes, stopping every 30 seconds to stir until completely smooth and melted. You can also melt the butter and chocolate together over low heat on the stove.
Add the sugar, vanilla and salt to the chocolate mixture. Whisk to combine. Add the eggs one at a time, whisking until fully incorporated after each egg. Stir in the gluten- free flour until incorporated.
Pour the batter into the prepared baking pan. Smooth into an even layer. Bake for 30-35 minutes until set and a toothpick inserted into the center of the brownies comes out clean. Let the brownies cool completely.
Make the Peanut Butter Crunch:
Spread the marshmallow creme over evenly over the cooled brownies. In a saucepan over medium-low heat add the peanut butter and chocolate chips. Stir until melted. Remove from the heat and stir in the cocoa Pebbles cereal.
Smooth the crunch mixture over top of the brownies. Refrigerate for 30 minutes to set. Cut into bars and serve. Brownies can be stored in the fridge for up to 3 days. Enjoy!