Preheat the oven to 350 degrees then spray an 8x8” baking pan with nonstick spray or line with parchment paper and set aside.

To a medium-sized mixing bowl add the gluten free flour blend, graham cracker crumbs, baking powder, and salt then whisk to combine and set aside.

To the bowl of an electric stand mixer, or large glass bowl if using a hand-held mixer, add the butter and brown sugar. Beat on medium-high speed for 2 minutes or until the mixture is light and creamy, scraping down the sides of the bowl halfway through.

Scrape down the sides of the bowl then add the egg and vanilla then mix on low until just combined. Add the flour and graham cracker mixture then mix on low until combined. Let the dough rest for 5 minutes.

Scoop a little more than half the dough into the prepared baking pan then press into an even layer in the bottom — it helps to slightly wet your fingers with water first.

Dollop the marshmallow crème or fluff on top then use the back of a spoon to spread it into an even layer — it helps to dip the back of the spoon in water, and don’t stress if it’s not perfect!

Sprinkle the chocolate chips evenly over the top of the marshmallow layer then use a cookie scoop to dollop scoops of the remaining dough on top. Bake for 32-35 minutes or until the top is browned and the bars have set, rotating the baking pan 180 degrees halfway through. The marshmallow fluff will puff up between the cookie scoops — that's ok! Er on the side of slightly over-baking, vs underbaking.

Cool bars completely then let sit for at least 12 hours before slicing into squares and serving. The bars will slice more cleanly if the bars are refrigerated first. Store leftover bars on the counter for 2-3 days, or in the refrigerator for up to 5 days.