Step 1

Line an 8x8-inch baking dish with parchment paper and lightly spray it with nonstick spray. Set it aside.

Step 2

Add the all-purpose flour to a small microwave-safe bowl. Microwave for 1 minute. Allow the flour to cool completely. Once the flour is completely cooled, sift the flour to remove any small clumps.

Step 3

Add 1 cup of the plain M&M’s and ½ cup of the mini M&M’s to quart-size Ziploc bags. Place both in the freezer while making the rest of the recipe.

Step 4

Using a medium-sized mixing bowl and a handheld mixer, cream the butter, granulated sugar, light brown sugar, half and half, vanilla extract, and salt for 1½-2 minutes.

Step 5

Reduce the mixer speed to low, add the flour, and mix just until the ingredients are well incorporated. Set it aside.

Step 6

In a heat-safe medium-sized bowl, heat the white chocolate chips and sweetened condensed milk in the microwave for 30 seconds at a time, stirring well after each 30 seconds, until the chips are completely melted and smooth.

Step 7

Remove the Ziploc bags from the freezer. Using a wooden spoon, stir the frozen M&M’s into the butter and flour mixture.

Step 8

Spoon the white chocolate mixture into the cookie dough. Stir just until all ingredients are combined.

Step 9

Spoon the cookie dough fudge into the prepared baking dish.

Step 10

Evenly sprinkle the remaining M&M’s and mini M&M’s on top of the cookie dough fudge. Very gently press the M&M’s into the top of the fudge. Cover tightly and refrigerate for at least 2 hours to overnight.

Step 11

Remove the fudge from the refrigerator and slice the fudge into 25 squares, 5 pieces across and 5 pieces down.