Preheat the oven to 350°F. Lightly grease a pizza pan or line it with parchment paper.
In a large mixing bowl, beat the softened butter and packed brown sugar until smooth and creamy.
Add the egg and vanilla extract, then mix until fully combined.
Add the graham cracker crumbs, all-purpose flour, baking soda, and salt. Mix until a soft cookie dough forms.
Press the dough evenly onto the prepared pizza pan, shaping it into a round pizza crust.
Bake for 12 minutes, or until the crust is lightly golden and set.
Remove the crust from the oven and sprinkle the chocolate chips evenly over the warm crust. Add the mini marshmallows on top.
Place the pizza under the broiler for 2 minutes, just until the marshmallows are golden and toasted. Watch closely because marshmallows can burn very quickly.
Sprinkle with extra graham cracker crumbs and drizzle with melted chocolate, if desired.
Let the s’mores pizza cool for a few minutes before slicing and serving.
