Step 1

Preheat oven to 275°F and line a baking sheet with parchment paper.

Step 2

In a medium bowl add crushed cornflakes, powdered milk, sugar, and salt. Toss to combine.

Step 3

Pour in the melted butter and toss again. (Small cornflake clusters will form).

Step 4

Pour the mixture onto the baking sheet and bake for 20 minutes (or until the cereal is slightly toasted).

Step 5

Cool completely. Then, break up any large clusters into bits.

Step 6

Preheat oven to 350°F and spray a 9x13-inch pan with nonstick cooking spray.

Step 7

In the bowl of a stand mixer, add butter, granulated sugar, and brown sugar. Mix on medium until creamy (about 2 minutes).

Step 8

Add egg and vanilla and continue mixing for 8 minutes. (Yes, 8 minutes, to aerate the dough.)

Step 9

Add all-purpose flour, bread flour, baking soda, baking powder, and salt and mix on low until just incorporated.

Step 10

Gently fold in the cooled cornflake crunch.

Step 11

Divide dough in half and place half into the base of the 9x13-inch pan. Press down into an even layer.

Step 12

Top with Hershey bars and mini marshmallows.

Step 13

Top with the other half of dough in an even layer (all the way to the edges).

Step 14

Bake for 25-30 minutes, or until golden brown.

Step 15

Let the bars cool before serving.