01 -
Preheat the oven to 350°F. Grease a 9x13-inch baking dish and set aside.
02 -
In a large bowl, stir together flour, oats, brown sugar, salt, and 1 cup of softened butter until blended. Remove 1 cup of this mixture and set aside.
03 -
Press the remaining oat mixture evenly into the bottom of the prepared baking dish.
04 -
In a medium saucepan over medium-low heat, combine sweetened condensed milk, milk chocolate chips, and the remaining 2 tablespoons of butter. Stir constantly until smooth and fully combined.
05 -
Pour the chocolate mixture over the pressed oat base layer and spread evenly. Sprinkle the reserved oat mixture over the chocolate layer.
06 -
Scatter M&M’s evenly over the top and bake for 25 to 30 minutes until set and edges are lightly browned.
07 -
Allow bars to cool completely in the pan before cutting into 15 servings.