
A delightful Sour Cream Cookie Bar recipe that transforms traditional sugar cookies into something extra special. Each bar features a tender, cakey base made tangy with sour cream, topped with fluffy colorful frosting and festive sprinkles - creating the perfect balance of flavors and textures.
This recipe was born from my love of shortcuts without sacrificing flavor. The addition of sour cream creates a uniquely tender texture that elevates these bars above ordinary sugar cookies.
Essential Ingredients
- Full-fat Sour Cream: Room temperature
- Unsalted Butter: Room temperature
- All-Purpose Flour: For structure
- Large Egg: Room temperature
- Fresh Lemon Juice: For tang
- Pure Vanilla Extract: For flavor
- Powdered Sugar: For frosting
- Rainbow Sprinkles: Optional
- Food Coloring: As desired
STEP-BY-STEP PREPARATION
- 1. Initial Setup:
- Bring butter, egg, and sour cream to room temperature - crucial for proper mixing. Preheat oven to 350°F. Line a 9x9-inch pan with parchment, creating a sling for easy removal.
- 2. Cookie Base:
- Cream butter and sugar until light and fluffy, about 3 minutes. Add sour cream, egg, lemon juice, and vanilla. Mixture may look curdled - this is normal. Add flour and mix just until combined.
- 3. Baking Process:
- Spread dough evenly in prepared pan, ensuring corners are filled. Bake for 30-35 minutes until edges are golden brown and top is lightly golden. Cool completely on wire rack.
- 4. Frosting Creation:
- Beat butter until creamy. Gradually add powdered sugar, vanilla, and salt. Add food coloring if desired. Beat until light and fluffy. Spread over cooled bars.
- 5. Final Touch:
- Top with sprinkles immediately after frosting. Let sit for 30 minutes at room temperature or chill for 20 minutes for cleaner cuts. Cut into 16 squares.

The secret to perfect texture lies in the sour cream. As my grandmother would say, "A little tang makes everything more interesting."
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Storage and Make-Ahead Success
Store bars in an airtight container at room temperature for up to 3 days, layering parchment paper between layers to prevent sticking. For longer storage, refrigerate up to a week or freeze for up to 3 months, wrapping individually in foil. The unfrosted base can be made a day ahead, but it's best to frost the day of serving.
Temperature and Serving Variations
These bars are best served at room temperature when the texture is perfectly tender. If refrigerated, let stand for 15-20 minutes before serving. For parties, arrange on a tiered platter with different colored frostings and sprinkle combinations. During holidays, coordinate frosting colors and sprinkles with the season.

Creative Adaptations
Transform these bars for any occasion by varying frosting colors and sprinkle choices. Add almond or lemon extract for different flavor profiles. Create marble effects in the frosting, or divide into sections with different colors for celebrations. Make them extra festive with themed sprinkles, edible glitter, or custom decorations. The basic recipe provides a perfect canvas for creative expression.
Frequently Asked Questions
- → Why do ingredients need to be room temperature?
- Room temperature ingredients blend better for a smoother, more even texture in the bars.
- → Can I make these ahead?
- Yes, they can be made 2-3 days ahead and stored in an airtight container.
- → Why use a parchment sling?
- It makes removing and cutting the bars much easier and cleaner.
- → Can I freeze these bars?
- Yes, freeze unfrosted bars for up to 3 months, frost after thawing.
- → Can I double the recipe?
- Yes, use a 9x13-inch pan and increase baking time by 5-10 minutes.