Preheat the oven to 350 degrees. Line a baking sheet with parchment paper.
In a medium bowl, using a stand mixer or hand mixer, blend cool butter and sugar.
Add egg and vanilla.
Gradually add the flour and salt a little at a time so the flour doesn’t fly all over. You can do this by hand if you prefer, just be sure that it is combined well.
Roll out the dough into a circle on the parchment lined baking sheet. Bake for approximately 18 minutes, or until the center is baked through and the edges have barely changed color, if at all.
Remove from the oven and sprinkle with toppings.
Turn the oven to broil and return the pizza to the oven watching the toppings very carefully. As soon as the marshmallows are toasty, remove from the oven. This should only take a minute or two.
Enjoy right away or store at room temp until ready to dig in!