Extra Thick Chewy M&M Brownies

These ultra-thick M&M’s brownies are made by improving boxed brownie mix to create extra-soft, chewy, and fudgy bars that stay tender for days. Pick any M&M color scheme to match holidays, parties, or bake sales — they always disappear fast.

stack of three thick and fudgy m&m brownies with lots of candies sprinkled around them.

Equipment Checklist

This recipe is refreshingly simple and requires minimal equipment. No stand mixer needed — just a few basic tools you probably already own.

Mixing bowls

Use one large bowl for the dry ingredients and another for the wet ingredients to keep mixing tidy and efficient.

Parchment paper

Lining the pan with parchment makes transferring and cleanup much easier.

Metal 9×13 baking pan

A metal pan gives the most even bake and helps produce the ideal chewy edges and tender center.

Sharp carving or granton-edge knife

Use a thin, sharp knife and wipe it between slices to get neat, clean brownie pieces.

close up view of a thick brownie studded with m&ms with more brownies shingled in the background.

Why you’ll love these M&M Brownies

  • Semi-homemade, elevated — Boxed brownie mix is a huge time-saver. With a few enhancements you get bakery-style texture without a lot of fuss.
  • Extra-thick bars — This recipe doubles the dry mix so the brownies are tall, soft, and satisfyingly chewy in every bite.
  • Colorful and fun — A generous amount of M&M’s brightens the bars for any occasion. Swap colors to match holidays, team themes, or celebrations.
overhead view of all the ingredients to make fudgy m&m brownies including water, oil, brownie mix, eggs, and more.

Ingredients

Boxed mixes are not cheating — they contain flour, cocoa, sugar, and leaveners so you can focus on improving texture and flavor with a few extra ingredients.

This version adds ingredients that produce a moist, tender, bakery-style brownie while keeping the method easy and fast.

  • Boxed brownie mix — 2 family-size mixes (choose mixes intended for a 9×13 pan)
  • Instant Clearjel — a small amount to help keep the brownies soft and stable (do not substitute with cornstarch)
  • Dark Dutch-process cocoa powder — for deeper chocolate flavor
  • Water
  • Vegetable oil — contributes to moist crumb and chew
  • Eggs — provide structure and richness
  • M&M candies — about 2 cups total, reserve a handful to sprinkle on top
  • Vanilla extract — for balance and aroma

Baker’s Tip

These brownies improve after resting and are often best the next day once flavors have settled. Bake ahead for events and they’ll still be tender and fudgy.

Full ingredient amounts and measurements are listed in the recipe card below.

Variations

This recipe adapts a bakery-style brownie concept — swap mix-ins and candy colors to suit the occasion. Use red and green M&M’s for Christmas, pink and white for Valentine’s Day, or team colors for sports events.

Try different mix-ins: replace some M&M’s with dark chocolate chips, chopped nuts, crushed pretzels, caramel chips, or mini M&M’s for variety in texture and flavor.

antique pie plate with christmas themed M&M brownies with red and green M&M candies.
side view of a sliced m&m brownie with lots candies inside and sprinkled over top.

Storage

Thanks to the Instant Clearjel and oil, these brownies remain moist and tender for several days. Store leftovers in an airtight container at room temperature to prevent drying. They can also be refrigerated if your kitchen is warm — allow to come to room temperature before serving for best texture.

Key Recipe Notes

  • Don’t skip the Instant Clearjel. It’s the key ingredient that keeps the crumb soft and provides a bakery-style texture.
  • Monitor the bake time. After reducing the oven to 325°F, start checking at about 35 minutes. A toothpick inserted in the center should come out clean or with a few moist crumbs when done.
stack of homemade m&ms brownies shingled together on a white surface with a bowl of candies in the background.

These M&M brownies are irresistible. They offer the ideal balance of tender, fudgy crumb and chewy texture, with colorful candy in each bite. They’re perfect for bake sales, school parties, birthdays, and casual get-togethers.

Thanks for reading. ❤️

Amy's Signature

Recipe & Step-by-Step Instructions

Super Thick and Chewy M&M’s Brownie Recipe

These ultra-thick M&M brownies start with boxed mixes and a few key additions to make them soft and tender for days. Perfect for class parties, bake sales, birthdays, and holidays.
Servings 15 servings
Prep Time 10 mins
Cook Time 55 mins

Equipment

  • 9×13 cake pan

Ingredients

  • 4 large eggs
  • 1 1/3 cup vegetable oil
  • 1/2 cup water
  • 1 teaspoon vanilla extract
  • 2 x 18.3 oz boxed brownie mixes (family-size for 9×13)
  • 2 Tablespoons dark Dutch-process cocoa powder
  • 1 Tablespoon + 1 teaspoon Instant Clearjel
  • 2 cups M&Ms (reserve some for topping)

Instructions

  1. Preheat the oven to 350°F. Line a 9×13 cake pan with parchment paper on the bottom and up the sides so the brownies lift out easily.
  2. In a very large bowl, whisk together the two brownie mixes, Instant Clearjel, and dark cocoa powder until evenly combined.
    whisking brownie mixes and dry ingredients in a large mixing bowl.
  3. In a separate bowl, whisk the eggs until smooth. Add the vegetable oil and water and whisk to combine. Stir in the vanilla.
    adding vegetable oil to whisked eggs.
  4. Pour the wet ingredients over the dry ingredients and fold together with large strokes until no dry streaks remain. Avoid overmixing to keep the brownies tender.
    mixing wet and dry ingredients for brownie batter.
  5. Fold in about 1 cup of M&Ms, then spread the batter into the prepared pan. Sprinkle the remaining M&Ms over the top so each square has visible candy.
    brownie batter with m&ms before baking.
  6. Bake at 350°F for 20 minutes, then reduce the oven to 325°F and bake another 35–50 minutes, or until a toothpick inserted in the center comes out clean or with a few moist crumbs. Baking time varies by oven and pan; check early. Allow to cool completely before slicing. These brownies reach their best texture after cooling for several hours or chilling overnight.
    freshly baked thicker M&M brownies cooling.
Author: Amy
Course: Dessert
Cuisine: American
Keyword: bakery-style, brownies with m&ms, m&m brownies