Gooey Chocolate Chip Sandwich Bars

Ingredients (17)

• GOOEY CHOCOLATE FILLING:
• 2 cups semisweet chocolate chips
• One 14-ounce can sweetened condensed milk
• 2 teaspoons vanilla extract
• COOKIES:
• 1 cup (2 sticks) unsalted butter,
• 1 cup packed light brown sugar
• 1/2 cup granulated white sugar
• 1 large egg
• 1 large egg yolk
• 1 tablespoon vanilla extract
• 2 cups all purpose flour
• 1 cup quick-cooking or old fashioned rolled oats
• 1 teaspoon baking powder
• 1 teaspoon baking soda
• 1 teaspoon kosher salt
• 3 cups semisweet chocolate chips