Grain-Free Birthday Blondies

Soft and chewy, these blondies are a fun treat for everyone — especially for those following a keto-friendly or grain-free lifestyle. Browned butter gives these tender bars a deliciously complex flavor, while sugar-free white chocolate baking chips and sugar-free sprinkles make them the perfect fit for any celebration. 

Looking to make these blondies with conventional sugar instead of Baking Sugar Alternative? See "tips," below for details.

20 mins
20 to 24 mins
1 hr
16 medium (2”) squares
Grain-Free Birthday Blondies - select to zoom
Grain-Free Birthday Blondies - select to zoom
Grain-Free Birthday Blondies - select to zoom
Grain-Free Birthday Blondies - select to zoom


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  1. Preheat the oven to 325°F. Lightly grease an 8” square pan, line the bottom with parchment, and lightly grease the parchment.

  2. To brown the butter: In a saucepan set over medium heat, melt the butter. When fully melted the butter will start to sizzle and may spatter and pop a bit.

  3. Continue to cook the butter, swirling the pan regularly until it’s a rich golden brown, with brown bits at the bottom of the pan. The sizzling will have stopped, and there may be a layer of foam on the surface.

  4. To make the blondies: Remove the pan of butter from the heat and pour the liquid butter (and brown bits) into a heatproof medium-sized mixing bowl.

  5. Add the baking sugar alternative to the browned butter and whisk to combine.

  6. Add the egg, egg yolk, and vanilla extract.

  7. In a small bowl whisk together the flours, baking powder, and salt.

  8. Stir the dry ingredients into the butter mixture, followed by the sugar-free chips and sprinkles.

  9. Spread the mixture evenly in the pan and top with additional sprinkles and baking chips, if using.

  10. To bake the blondies: Bake the blondies for 20 to 24 minutes, until they're set in the middle, golden brown, and just starting to pull away from the sides of the pan.

  11. Remove them from the oven, loosen their edges with a table knife, and cool completely before cutting.

  12. Storage information: Store any leftovers, well wrapped, at room temperature for up to a week; freeze for longer storage.

Tips from our Bakers

  • While we recommend browning the butter for more flavor, these blondies can also be made using 7 tablespoons (99g) melted butter. Mix and bake as directed.

  • This recipe was developed using King Arthur Baking Sugar Alternative. Using another sugar replacement or alternative, one with a different formulation, will yield different results. For best success, use the specific product called for: King Arthur Baking Sugar Alternative.

  • If you'd like to make these blondies with conventional sugar, replace the Baking Sugar Alternative with 2/3 cup (142g) of brown sugar, packed. Instead of using sugar-free white chocolate chips and sprinkles, feel free to use 1/3 cup of the mix-ins of your choice (white chocolate chips, chocolate chunks, nuts, etc.) and conventional sprinkles. Increase the baking time to 22 to 26 minutes; blondies will be golden brown, set in the middle, and just starting to pull away from the sides of the pan when done.