01 -
Turn your oven on to 350°F. Cover an 8x8-inch pan with foil and add a quick spray of nonstick cooking spray.
02 -
Pop the butter into a microwave-safe bowl and heat it until it’s melted. Let it cool a bit first before you move on.
03 -
Toss in the peanut butter, egg, brown sugar, and vanilla with the melted butter. Whisk till it’s all blended and smooth.
04 -
Add the flour to the wet mix. Stir just enough to combine everything without overdoing it.
05 -
Gently mix ½ cup of M&M's into the batter so they’re evenly spread out.
06 -
Pour the batter into the pan you prepped earlier, smoothing out the surface. Scatter the last ¼ cup of M&M's on top and lightly press them in.
07 -
Slide it into the oven and bake for 22-26 minutes. Check by poking a toothpick in—if it comes out mostly clean or just a bit crumby, it’s done!
08 -
Leave the blondies in the pan to cool for at least an hour before slicing them up.