Instructions

• Preheat oven to 350°F and spray an 8x11-inch baking pan with cooking spray.
• In a large bowl, beat 1/2 cup slightly softened unsalted butter and 1 cup lightly packed brown sugar until well combined.
• In a separate bowl, stir together 1 1/3 cups all-purpose flour, 1 cup old-fashioned oats, 1 teaspoon baking powder, and 1/2 teaspoon salt.
• Add the dry mixture to the butter–sugar mixture and stir until it forms a coarse crumb.
• Press half of the crumb mixture firmly and evenly into the bottom of the prepared pan to form the crust.
• In another bowl, whisk together 1 (14 ounce) can sweetened condensed milk, 1/2 cup lemon juice, and the zest of 1 lemon until smooth.
• Pour and spread the lemon-condensed milk mixture evenly over the pressed crust.
• Break the remaining crumb mixture into small clumps with your fingers or a fork and evenly crumble it over the lemon layer.
• Bake for 20 to 25 minutes, or until the top is golden brown and the filling is set.
• Remove the pan from the oven and let it sit at room temperature for 30 minutes.
• Refrigerate the pan for a couple of hours, or until the bars are completely chilled and firm.
• Cut into squares and serve cool.