1 large egg
1 cup light brown sugar, packed
1 tablespoon vanilla extract
1 cup all-purpose flour
1/2 teaspoon salt, or to taste
18 Oreo cookies, roughly
1/2 cup M&M's
- Preheat oven to 350F.
- Line an 8-by-8-inch baking pan with aluminum foil, spray with cooking spray; set aside.
- To a large, microwave-safe bowl add the butter and heat to melt, about 1 minute on high power.
- Wait momentarily before adding the egg so you don't scramble it. Add the egg, brown sugar, vanilla, and whisk until smooth.
- Add the flour, salt, and stir until just combined, don't overmix.
- Add the Oreos and stir to combine.
- Add the M&M's and stir to combine.
- Turn the batter out into prepared pan, smoothing it lightly with a spatula and pushing it into the corners.
- Place a few Oreos and M&M's on top for visual appeal.
- Bake for about 18 to 21 minutes, or until top is set in center and done; don't overbake. Bars firm up as they cool.
- Place pan on a wire rack to cool for at least 90 minutes before slicing and serving.