Yields 2-3 dozen
1 1/2 cups steel-rolled, old-fashioned oats
1 1/2 cups semisweet chocolate chips
1 1/3 cups all-purpose flour
2/3 cup brown sugar
1/2 cup (1 stick) unsalted butter, divided
1/2 (14 oz.) can sweetened condensed milk
1 large egg
1 teaspoon vanilla extract
1/2 teaspoon baking soda
1/4 teaspoon salt
Preheat oven to 350 F and line a 8×8 or 9×9-inch baking dish with parchment paper and lightly spray with non-stick spray.
Combine flour, oats, baking soda and salt in a small bowl.
In a large bowl or mixer, cream together 6 tablespoons butter and sugar and lightened in color and fluffy.
Beat in egg and vanilla extract, then slowly beat in dry ingredients.
Set up a double boiler (or at 30-second intervals in the microwave), and melt condensed milk, chocolate chips and remaining butter over a simmering pot of water. Stir until completely melted and smooth.
Spread 2/3 of cookie dough mixture and pack it into baking dish.
Top with melted chocolate and gently tap the dish against a hard surface so that it spreads out and evenly coats the dough.
Spoon remaining cookie mixture over the top of chocolate, place in oven and bake for 25-30 minutes, or until top is golden brown.
Remove from oven and let cool completely before cutting into 1×2-inch squares.