Yield: 1 (9 by 13-inch) pan, about 32 servings (I make 3 cuts the long way and 7 cuts the short way)
Ingredients
¾ cup (160 g) lightly packed light brown sugar
12 tablespoons (170 g) unsalted butter, at room temperature, plus more to grease the dish
1 large egg
2 teaspoons pure vanilla extract
2 cups (255 g) all-purpose flour
2¼ cup (180 g) old-fashioned rolled oats, divided
½ cup (55 g) toasted walnuts, chopped
¾ teaspoon fine salt, divided
½ teaspoon baking powder
¼ teaspoon ground cinnamon
1 (14 oz/396 g) can sweetened condensed milk
1 (11 oz/311 g)) bag butterscotch chips
Sea salt (such as fleur de sel), for sprinkling on top
Instructions
Preheat oven to 350F; line a 9 by 13-inch glass dish with 2 pieces of parchment paper so that they hang over the edges (so you can easily pull the bars out later). Grease the inside with butter.
Stir together the brown sugar and butter in a large bowl, and then stir in the egg and vanilla extract. Stir in the flour, 2 cups oats, walnuts, ½ teaspoon salt, baking powder, and cinnamon.
Spread ⅔ of the oat mixture into the bottom and slightly up the sides of the prepared dish.
Melt the sweetened condensed milk, butterscotch chips, and remaining ¼ teaspoon salt together in a double boiler or microwave until smooth. Spread onto the crust, and then sprinkle the remaining oat mixture and remaining ¼ cup oats on top.
Bake until golden brown, about 20 to 22 minutes. Transfer to a wire rack and cool completely; sprinkle a little sea salt on top and cut into small squares. Store any leftovers in an airtight container at room temperature.
Notes
Recipe inspired by and adapted from Cooking Light’s recipe for Butterscotch Bars.
Recipe by An Edible Mosaic™ at https://www.anediblemosaic.com/salted-butterscotch-oat-bars/