These s’mores blondies are one of those treats that seem simple, but they hit all the right notes: buttery, chewy, chocolatey, and gooey on top. I guarantee they won’t last long on your counter. Whether you’re baking for a summer get-together or just need a little weekday joy, this is a recipe worth saving.
Line an 8×8-inch pan with aluminum foil and spray lightly with non-stick spray. Preheat your oven to 350 F (175 C) for conventional oven. If using convection oven, lower temperature by 20 F (15 C)
Position your oven racks, one on the upper 3rd and another one on the lower 3rd. We will move the position of the pan halfway through baking later
Make the blondie batter:
In a mixing bowl fitted with the paddle attachment, beat the softened butter, brown sugar, granulated sugar, and vanilla on medium speed for 4–5 minutes until light and creamy. Add the egg and beat just until combined.
Add the dry ingredients:
Mix in the graham cracker crumbs, flour, baking powder, and salt. Beat briefly until just combined
Then fold in the chopped dark chocolate.
Bake – part 1:
Spread the batter evenly into the prepared pan.
Bake on the lower third rack for 30 minutes.
Add marshmallows and continue baking:
Remove from the oven, scatter the mini marshmallows over the top, and move the pan to the upper third rack.
Bake for another 8 minutes or until the marshmallows are just lightly golden.
Final chocolate hit:
Scatter the remaining dark chocolate over the marshmallow layer and bake for an additional 3 minutes.
Cool completely:
Let the blondies cool completely in the pan before lifting them out and slicing. They’ll set up nicely as they cool. I thought I was going to make the chocolate "swirl" but it ended up looking ugly LOL! So, just leave the chocolate as is guys!