Ultra-Thick Lofthouse Cookie Bars
Soft, ultra-thick Lofthouse cookie bars baked in an 8x8 pan and topped with fluffy pink buttercream and rainbow sprinkles. All the bakery-style frosted sugar cookie flavor with no rolling, cutting, or chilling the dough.
Servings: 9 bars
Calories: 634kcal
Equipment
- 8x8 baking pan
- Parchment paper
- Electric mixer
- Mixing bowls
- Offset spatula
Ingredients
Cookie Bars
- ¾ cup butter, softened
- ¾ cup granulated sugar
- 1 large egg
- 1 large egg yolk
- 2 teaspoons vanilla extract
- ⅓ cup sour cream
- 2 cups + 2 tablespoons all-purpose flour, spooned and leveled
- ¾ teaspoon baking powder
- ¼ teaspoon baking soda
- ½ teaspoon fine salt
Pink Frosting
- ½ cup butter, softened
- 2 cups powdered sugar
- 2-3 tablespoons milk
- 1 teaspoon vanilla extract
- Pinch of salt
- 1-2 drops pink food coloring, gel preferred
- Sprinkles, for topping
Instructions
Make the Cookie Bars
- Preheat the oven to 350°F and line an 8x8 pan with parchment, leaving an overhang on two sides.
- Cream 3/4 cup softened butter and 3/4 cup granulated sugar until light and fluffy, about 2 minutes.
- Mix in 1 large egg, 1 egg yolk, and 2 teaspoons vanilla extract until smooth.
- Stir in 1/3 cup sour cream until the batter looks glossy.
- Add 2 cups + 2 tablespoons all-purpose flour, 3/4 teaspoon baking powder, 1/4 teaspoon baking soda, and 1/2 teaspoon fine salt. Mix just until a thick dough forms.
- Press the dough evenly into the pan, using lightly floured fingertips to push it into the corners.
- Bake 22 to 27 minutes, until the edges are lightly golden and the center is just set.
- Cool the bars completely, then chill in the refrigerator until ready to frost.
Make the Pink Frosting
- Beat 1/2 cup softened butter, 2 cups powdered sugar, 2 to 3 tablespoons milk, 1 teaspoon vanilla extract, and a pinch of salt until fluffy, about 3 minutes. Add 1 to 2 drops pink food coloring and beat to combine.
- Spread the frosting over the cooled bars, top with sprinkles, and chill 10 to 15 minutes before slicing into 9 squares.
Notes
Storage: Store frosted bars in an airtight container in the refrigerator for up to 5 days. Let them sit out about 20 minutes before serving so the frosting softens. Unfrosted bars keep at room temperature for 3 days.
Freezing: Freeze unfrosted bars, wrapped tightly and bagged, for up to 3 months. Thaw at room temperature and frost the day you serve them.
Do not overbake. Pull the pan when the center still looks slightly underdone. The bars firm up as they cool and stay soft for days.
Spoon and level the flour instead of scooping. Packed flour makes the bars dry and cakey.
Sour cream swap: Plain full-fat Greek yogurt works as a straight 1:1 substitute.
Nutrition values are estimates.
Nutrition
Calories: 634kcal | Carbohydrates: 87g | Protein: 7g | Fat: 29g | Saturated Fat: 18g | Polyunsaturated Fat: 1g | Monounsaturated Fat: 7g | Trans Fat: 1g | Cholesterol: 113mg | Sodium: 376mg | Potassium: 128mg | Fiber: 2g | Sugar: 44g | Vitamin A: 903IU | Vitamin C: 0.1mg | Calcium: 49mg | Iron: 3mg