This Funfetti Sugar Cookie Cake combines the crisp golden edge of a giant cookie with a soft, chewy center. Rainbow jimmies make it celebration-ready, while the one-pan format keeps the method much simpler than a layer cake.
Why This Recipe Works
- Balanced texture: The extra egg yolk keeps the center tender while the edge turns lightly golden.
- Clean color: Jimmies hold their shape better than tiny nonpareils and are less likely to bleed into the dough.
- Flexible finish: Serve the cookie cake plain or add a simple buttercream border for a party.
Ingredients
- 1 cup (226 g) unsalted butter, softened
- 1 1/4 cups (250 g) granulated sugar
- 1 large egg, at room temperature
- 1 large egg yolk, at room temperature
- 1 tablespoon pure vanilla extract
- 1/2 teaspoon almond extract (optional)
- 2 1/4 cups (280 g) all-purpose flour
- 1/2 teaspoon baking soda
- 1/2 teaspoon baking powder
- 1/2 teaspoon fine salt
- 1/2 cup (90 g) rainbow jimmies sprinkles
Optional Vanilla Buttercream Border
- 1/2 cup (113 g) unsalted butter, softened
- 1 1/2 cups (180 g) powdered sugar
- 1 teaspoon vanilla extract
- 1 to 2 tablespoons milk or cream
- Extra rainbow jimmies, for decorating
Step-by-Step Instructions
1. Prepare the Pan
Preheat the oven to 350°F (175°C). Grease a 9-inch round cake pan, then line the bottom with a fitted parchment circle so the cookie cake releases cleanly.
2. Cream the Butter and Sugar
Beat the softened butter and granulated sugar with an electric mixer for about 2 minutes, until pale and fluffy. Scrape the bowl once so no dense butter remains at the bottom.
3. Add the Eggs and Flavorings
Beat in the whole egg and extra yolk until smooth. Mix in the vanilla and optional almond extract, then scrape the bowl again.
4. Combine the Dry Ingredients
In a separate bowl, whisk the flour, baking soda, baking powder, and salt until evenly distributed. Add this dry mixture to the wet ingredients in two additions and mix only until no dry streaks remain.
5. Fold in the Sprinkles
Use a spatula to fold the rainbow jimmies through the thick dough. Stop as soon as they are evenly dispersed to keep the cookie cake tender and prevent the colors from smearing.
6. Press the Dough into the Pan
Transfer the dough to the prepared pan. Press it into one level layer, taking care to fill the edge evenly so the cake bakes at the same rate throughout.
7. Bake Until Just Set
Bake for 22 to 25 minutes, until the edge is lightly golden and the center looks set but remains soft. Avoid waiting for the entire top to brown; residual heat will continue cooking the center.
8. Cool, Decorate, and Serve
Cool in the pan for 15 minutes, then turn the cookie cake onto a wire rack and let it cool completely before slicing. For the optional border, beat the softened butter with the powdered sugar and vanilla, adding just enough milk for a pipeable consistency. Pipe small rosettes around the cooled edge and finish with a few jimmies.
Helpful Tips
- Use room-temperature ingredients: They blend more evenly and help create a consistent crumb.
- Measure flour carefully: Spoon it into the measuring cup and level it, or weigh 280 grams.
- Choose jimmies: Tiny nonpareils bleed more readily and can muddy the dough.
- Do not overbake: The center should finish setting while the cookie cake cools.
- Decorate only when cool: Buttercream melts on a warm cookie cake.
Store the undecorated cookie cake tightly covered at room temperature for up to 3 days. If decorated with buttercream, keep it covered in a cool place or refrigerate it and bring slices back to room temperature before serving.