These gluten-free blondies are super moist and chewy, just like a soft-baked chocolate chip cookie. Please note this recipe has been updated January 2022.
Preheat the oven to 350º F and line the bottom of an 8" x 8" or 9" x 9" square pan with parchment paper. Lightly spray cooking spray over the parchment paper and exposed sides of pan.
Combine the flour, baking powder and salt in a medium bowl and whisk together.
In a separate medium bowl, add melted butter and brown sugar and mix until well combined, then whisk in the egg, egg yolk, and vanilla extract.
Add half of the flour mixture to the butter mixture and mix well. Add the second half of the flour mixture and continuing mixing. I use a rubber spatula to scrape the sides and mix everything together.
Fold in chocolate chips and allow batter to sit for 3-5 minutes. This will allow the flour to sufficiently soak up the wet ingredients.
Add the batter to your square baking pan and bake for 30-35 minutes or until a toothpick inserted in the center comes out clean. Remove from the oven and allow the blondies to cool completely in the pan over a wire rack. DO NOT cut the blondies until they're completely cooled, about 2 hours. Sometimes the blondies will sink a bit in the middle. I use a large flat spatula to gently press the ingredients flat.
Cut the blondies into 16 even squares and serve. Store in a sealed container for 2-3 days at room temperature or in your fridge for up to a week.
Notes
The cookies will be slightly crumbly on the outside, but they should be gooey and soft in the middle. Baking times can vary depending on your oven, pan size (8x8 vs 9x9, and altitude). Be sure to allow the blondies to cool completely before cutting. They are gooey in the middle and it'll be easier to cut into even, pretty squares when they're completely cooled. If using a different brand of gluten-free than recommended, make sure the flour blend contains xanthan gum. If not, add 1/2 tsp of xanthan gum for every cup of flour (i.e. add 1 tsp of xanthan gum for this recipe)