Christmas sugar cookie bars have the buttery vanilla flavor of a frosted sugar cookie without the rolling, chilling, and individual cutting. The dough bakes in one 9-by-13-inch pan, then gets a generous layer of vanilla buttercream and Christmas sprinkles. Cut them into small squares for a cookie tray or larger rectangles for a holiday dessert platter.
The trick to soft bars is keeping the dough tender and taking the pan out before the center looks completely firm. A lightly golden edge is enough. Once cooled and frosted, the bars should have a soft middle, a slightly firmer bottom, and enough structure to pick up with your fingers.
Christmas sugar cookie bars with vanilla buttercream
This recipe makes a thick sugar cookie base with a spreadable buttercream topping. There’s no need to chill the dough, and parchment paper makes it easier to lift the finished slab from the pan.
Yield: 24 bars
Prep time: About 25 minutes
Bake time: 22–28 minutes
Cooling time: About 90 minutes
Total time: About 2 hours 20 minutes
Equipment: 9-by-13-inch metal baking pan, parchment paper, electric mixer, mixing bowls, and a spatula
Ingredients
For the sugar cookie base
– 1 cup (226 g) unsalted butter, softened
– 1¼ cups (250 g) granulated sugar
– 2 large eggs, at room temperature
– 2 teaspoons (10 mL) vanilla extract
– 2¾ cups (330 g) all-purpose flour
– 1 teaspoon (4 g) baking powder
– ½ teaspoon (3 g) fine salt
For the vanilla buttercream
– ¾ cup (170 g) unsalted butter, softened
– 2½ cups (300 g) powdered sugar, sifted if lumpy
– 2 tablespoons (30 mL) heavy cream, plus up to 1 tablespoon (15 mL) more as needed
– 1½ teaspoons (7.5 mL) vanilla extract
– ⅛ teaspoon fine salt
– Gel food coloring, optional
– ¼ cup (about 40 g) Christmas sprinkles, or as desired
Instructions
1. Prepare the pan and oven. Heat the oven to 350°F (175°C). Lightly grease a 9-by-13-inch metal pan. Line it with parchment paper, leaving enough overhang on two opposite sides to lift out the bars.
2. Cream the butter and sugar. Beat the softened butter and granulated sugar with an electric mixer on medium speed for 2–3 minutes, until lighter in color and fluffy. Scrape down the bowl.
3. Add the eggs and vanilla. Beat in the eggs one at a time, mixing until each is incorporated. Add the vanilla and scrape the bowl again.
4. Mix in the dry ingredients. Whisk the flour, baking powder, and salt together in a separate bowl. Add them to the butter mixture and mix on low speed just until no dry flour remains. The dough will be thick and soft.
5. Press into the pan. Distribute spoonfuls of dough across the prepared pan, then press them into an even layer. A small piece of parchment placed over the dough helps keep it from sticking to your hands. Pay attention to the corners so they aren’t noticeably thinner than the center.
6. Bake. Bake for 22–28 minutes, checking at 22 minutes. The surface should look set, the edges should be just beginning to turn golden, and a toothpick inserted near the center should come out without wet dough. A few moist crumbs are fine. Avoid waiting for the entire top to brown.
7. Cool completely. Place the pan on a wire rack and let the cookie base cool completely, about 90 minutes. Leave it in the pan while cooling so the warm slab has support.
8. Make the buttercream. Beat the softened butter until smooth. Add the powdered sugar gradually on low speed, then add 2 tablespoons of cream, the vanilla, and salt. Beat on medium speed for about 2 minutes, until fluffy. Add the remaining cream a teaspoon at a time if the frosting is too stiff to spread. Mix in gel food coloring, if using.
9. Frost and decorate. Spread the buttercream over the cooled cookie base. Add the sprinkles immediately and press them very lightly into the frosting.
10. Cut and serve. For neater edges, refrigerate the frosted slab for 20–30 minutes before cutting. Lift it out using the parchment, set it on a cutting board, and cut into 24 bars. Wipe the knife between cuts.
Getting a soft center without underbaking
Flour measurement makes a noticeable difference in soft sugar cookie bars. A kitchen scale is the most consistent option. Without one, fluff the flour, spoon it into the measuring cup, and level the top. Scooping directly from the bag can pack extra flour into the cup and produce a dry, dense bar.
The butter should yield to gentle pressure but still hold its shape. Melted or very greasy butter won’t cream the same way, and cold butter can leave lumps throughout the dough.
Once the flour goes in, keep mixing brief. Finish any stubborn flour pockets with a spatula rather than running the mixer longer than necessary.
Watch the bars closely near the end of baking. A metal pan usually gives more predictable results than glass for this recipe, though ovens and pan finishes vary. The center should be set, not wet or jiggly, when the pan comes out. It will firm up further as it cools.
Choosing frosting colors and Christmas sprinkles
White buttercream gives red and green sprinkles a clear background and keeps decorating simple. For colored frosting, add gel food coloring a little at a time. It takes less liquid than conventional liquid coloring, so it’s less likely to thin the buttercream.
Jimmies and small confetti sprinkles are comfortable to bite through and work well on these frosted sugar cookie bars. Nonpareils add a fine crunch, but their colors may bleed when exposed to moisture. For a tray prepared well ahead of serving, decorating closer to serving time can help preserve sharper colors.
Large sugar pearls can be quite hard. Use them sparingly, especially when serving young children. If using a mixed sprinkle blend, check the label for allergens and confirm that every decoration is edible.
Making, storing, and transporting the bars
For make-ahead holiday baking, the unfrosted cookie base can be baked a day in advance. Let it cool completely, then cover it tightly and keep it at room temperature until frosting.
Store frosted bars in an airtight container in the refrigerator for up to 4 days. Let individual portions stand at room temperature for about 20–30 minutes before serving so the cookie and buttercream soften. For a conservative serving limit, refrigerate them again within 2 hours, or within 1 hour if the temperature is above 90°F (32°C).
For longer storage, freeze the bars for up to 2 months for best quality. Freeze them uncovered until the frosting is firm, then transfer them to a freezer-safe container with parchment between layers. Thaw covered in the refrigerator. Some sprinkle colors may run during thawing, so an unfrosted base offers the tidiest make-ahead option.
Transport these holiday cookie squares in a single layer whenever possible. A snug container keeps them from sliding into one another, and chilled buttercream is less likely to smear. For a dessert table with several other sweets, cut the slab into 32 smaller pieces instead of 24; the smaller portions fit neatly among cookies, fudge, and other holiday treats.
