Preparation Steps

• Line an 8x8-inch baking dish with parchment paper and lightly spray it with nonstick spray. Set it aside.
• Heat-treat the all-purpose flour. Add it to a small microwave-safe bowl and microwave for 1 minute. Allow the flour to cool completely. Once cooled, sift the flour to remove any clumps.
  1 cup all-purpose flour
• In quart-size Ziploc bags, combine 1 cup of plain M&M's and 0.5 cup of mini M&M's for later. Place these bags in the freezer while preparing the rest of the recipe.
  1 cup all-purpose flour
• In a medium-sized mixing bowl, use a handheld mixer to cream together the softened butter, granulated sugar, light brown sugar, half and half, vanilla extract, and salt for 1.5 to 2 minutes until well combined.
  1 cup all-purpose flour
• Reduce the mixer speed to low. Add the heat-treated flour and mix just until the ingredients are well incorporated. Set the mixture aside.
  1 cup all-purpose flour
• In a heat-safe medium-sized bowl, combine the white baking chips and sweetened condensed milk. Heat in the microwave in 30-second intervals, stirring well after each interval, until the chips are completely melted and the mixture is smooth.
  1 cup all-purpose flour
• Remove the frozen M&M's bags from the freezer. Using a wooden spoon, stir the frozen M&M's into the butter and flour mixture.
• Spoon the white chocolate mixture into the cookie dough base. Stir just until all ingredients are combined.
• Spoon the cookie dough fudge into the prepared baking dish.
• 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, or preferably overnight, to set.
  1 cup all-purpose flour
• Remove the fudge from the refrigerator and slice into 25 squares (cut into 5 rows by 5 columns).