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4th of July Monster Cookie Bars Recipe

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3.9 from 1 review

Celebrate the 4th of July with these festive and chewy Monster Cookie Bars packed with peanut butter, oats, chocolate chips, and red, white, and blue M&M's and sprinkles. Perfect for a patriotic party treat, these bars combine classic cookie flavors with a fun, colorful twist and a soft, chewy texture.

  • Author: Lilya
  • Prep Time: 20 minutes
  • Cook Time: 30 minutes
  • Total Time: 50 minutes
  • Yield: 12 servings
  • Category: Dessert
  • Method: Baking
  • Cuisine: American

Ingredients

Wet Ingredients

  • ¾ cup unsalted butter (not margarine), softened
  • ¾ cup granulated sugar
  • ½ cup light brown sugar
  • 2 eggs
  • 3 tablespoons light corn syrup (or honey)
  • ¾ cup creamy peanut butter
  • 2 teaspoons vanilla extract

Dry Ingredients

  • 1 teaspoon baking soda
  • ½ teaspoon salt
  • 1 ¾ cups all-purpose flour
  • 1 ¾ cups quick oats

Add-ins and Toppings

  • 1 cup semi-sweet chocolate chips, divided (¾ cup in dough & ¼ cup on top)
  • 1 cup red, white, blue M&M's, divided (¾ cup in dough & ¼ cup on top)
  • ¼ cup red, white, blue sprinkles

Instructions

  1. Preheat Oven: Preheat your oven to 350°F to ensure it's ready once the dough is prepared.
  2. Cream Butter and Sugars: In a large bowl, use an electric mixer to cream together ¾ cup softened unsalted butter, ¾ cup granulated sugar, and ½ cup light brown sugar for 2 minutes until the mixture is light in color and fluffy.
  3. Add Eggs, Corn Syrup, and Vanilla: Beat in 2 eggs, 3 tablespoons light corn syrup, and 2 teaspoons vanilla extract until fully combined and smooth.
  4. Incorporate Peanut Butter and Leavening: Mix in ¾ cup creamy peanut butter until evenly combined. Then stir in 1 teaspoon baking soda and ½ teaspoon salt to help the bars rise and balance flavors.
  5. Add Flour and Oats: Gradually add 1 ¾ cups all-purpose flour and 1 ¾ cups quick oats, mixing just until combined to avoid overworking the dough, which keeps bars tender.
  6. Mix in Chocolate Chips and M&M's: Gently fold in ¾ cup semi-sweet chocolate chips and ¾ cup red, white, and blue M&M's, reserving the rest for topping.
  7. Spread Dough in Pan: Drop the sticky dough into a greased or parchment-lined 9x13 inch metal pan in small pieces. Spread and smooth with a spatula to an even layer. Sprinkle the remaining ¼ cup chocolate chips, ¼ cup M&M's, and ¼ cup sprinkles evenly over the top, gently pressing them into the dough.
  8. Bake: Bake in the preheated oven for 28-32 minutes until the edges and top are lightly golden brown and the center looks set but not dry. Avoid overbaking to maintain soft, chewy bars.
  9. Cool Completely: Remove from oven and place the pan on a cooling rack. Allow bars to cool fully before cutting to prevent crumbling and ensure clean slices.
  10. Slice and Serve: Once cooled, cut into 12 to 24 squares. Store leftover bars in an airtight container covered with plastic wrap for up to 3 days. For freezing, wrap bars tightly and freeze for up to 3 months.

Notes

  • Use a metal 9x13 inch pan for even baking and best texture.
  • The dough will be sticky; dropping it into small pieces in the pan helps spread it evenly.
  • Do not overbake; bars should be soft and chewy with lightly golden edges.
  • Allow bars to fully cool before cutting to prevent crumbling.
  • Store bars in an airtight container for up to 3 days; freeze for longer storage up to 3 months.
  • Substitute honey for light corn syrup if preferred.