We made a version of these lemon oat bars at a café I worked at in South Minneapolis, and they always sold out quickly. Over the years, I tinkered with the recipe by adding more sweetened condensed milk, a little salt, and some crème fraîche. They are great make-ahead bars, perfect for holidays, events, or just afternoon snacking.

　　This recipe was excerpted from '100 Cookies' by Sarah Kieffer. Buy the full book on Amazon. Get more of our favorite bar cookies →

　　

Ingredients

Makes 12 large or 24 small bars

　　

For the lemon filling

Two 14 oz (396 g) cans sweetened condensed milk

　　½ cup (120 g) lemon juice

　　3 Tbsp. heavy cream

　　1 Tbsp. lemon zest

　　½ tsp. pure vanilla extract

　　Pinch salt

　　

For the crust

2 cups (284 g) all-purpose flour

　　1½ cups (120 g) rolled oats

　　½ cup (100 g) brown sugar

　　¼ cup (50 g) granulated sugar

　　½ tsp. baking soda

　　½ tsp. salt

　　1 cup (2 sticks or 227 g) unsalted butter, at room temperature

　　

Step 1

Adjust an oven rack to the middle of the oven. Preheat the oven to 350°F. Grease a 9 by 13 inch (22 by 33 cm) pan and line it with a parchment sling.

　　

Make the filling

Step 2

In a large bowl, whisk together the sweetened condensed milk, lemon juice, heavy cream, zest, vanilla, and salt.

　　

Make the crust

Step 3

In the bowl of a stand mixer fitted with a paddle, mix the flour, oats, brown and granulated sugars, baking soda, and salt on low speed to combine. Add the butter and mix on medium speed until the mixture is crumbly.

　　

Assemble

Step 4

Press half of the oat mixture into the bottom of the prepared pan. Bake for 10 minutes. Remove the pan from the oven and carefully spread the filling over the crust. Sprinkle the remaining oat mixture evenly over the top. Bake for 15 to 20 minutes, until the filling is set and does not jiggle and the crumbly top is light golden brown.

　　

Step 5

Transfer the pan to a wire rack and let cool. Place the pan in the refrigerator and chill for 4 to 6 hours. Slice the bars and serve. The bars can be served cold or at room temperature but keep best in an airtight container in the refrigerator for about 3 days.

　　Reprinted from 100 Cookies: The Baking Book for Every Kitchen, with Classic Cookies, Novel Treats, Brownies, Bars, and More by Sarah Kieffer with permission by Chronicle Books, © 2020. Buy the full book from Amazon or Chronicle Books.