Description

One of the fastest, easiest bar cookies you can make also serves the most people. Bring a pan of these easy sheet pan Oatmeal M&M bars to a potluck, and there won’t be a single crumb leftover for the mice.

Ingredients

Scale

Cooking spray, for the pan
2 sticks butter (227 grams), at room temperature
3/4 cup granulated sugar (150 grams)
3/4 cup packed brown sugar (160 grams)
2 large eggs, at room temperature
1 tsp vanilla extract or vanilla paste
2 cups old fashioned rolled oats (190 grams)
2 cups all-purpose flour (260 grams)
3/4 tsp baking powder
1/2 tsp salt
12 oz bag of M&Ms, any color

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Instructions

Make the cookie dough

Spritz a baking sheet with enough cooking spray to make a piece of parchment
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stick to the pan. Press the parchment
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into the pan. Preheat the oven to 350 F (180C).
Cream the butter with the sugars on low speed (Kitchen Aid
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1 or with a hand mixer) for about 1 minute, just enough to make the sugars and butter into a smooth paste. It’s not necessary to beat more air into this mixture.
Add in the eggs, one at a time. Add in the vanilla and beat for a few more seconds.
Mix the flour, baking powder, salt, and about half the M&Ms in a bowl.
Scrape the bowl and beater well, paying attention to the bottom of the bowl which always likes to hide a little pocket of unmixed butter.
After you’ve finished scraping, pour in the dry ingredients (the mixer should be off!). Lower the mixer paddle into the whole mix, then carefully turn the mixer on then off rapidly. If you make this on/off motion in one little microsecond burst at a time, the flour won’t go everywhere. After a few power pulses, the mixer should be able to mix everything without flinging flour. Mix just until you see no flour–about 10 seconds.

Bake the sheet pan cookies

Scoop the dough into the middle of the cookie sheet.
Cover the dough with a piece of plastic wrap and press the dough into the corners of the pan. Start out doing this with your hands, and then if you have a small rolling pin
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, you can further press the dough into the corners.
Top the sheet of dough with the rest of the M&Ms. Lightly press the candy into the top of the dough.
Bake two prepared sheet pans of cookies for 18-20 minutes, just until the edges start to brown and the middle of the cookie feels set.
Allow the cookie sheet to cool about 5 minutes. Cut the cookie sheet into 32 bars (or more or less depending on how many people you want to serve. Serve the cookies straight from the pan.

Storing the cookies

You can store the cookies at room temperature for up to 2 days.
Freezing: freeze the whole sheet tray, covered with foil and plastic wrap or a sheet pan lid for up to 3 months.