Preheat your oven to 350°F (175°C). Grease a 12-inch pizza pan or line it with parchment paper.

In a medium bowl, whisk together the flour, baking soda, and salt. Set aside.

In a large mixing bowl, beat the butter, granulated sugar, and brown sugar until light and fluffy. Add the eggs and vanilla extract, mixing well. Gradually incorporate the dry ingredients until combined.

Spread the cookie dough evenly onto the prepared pizza pan, leaving about an inch from the edges to allow for spreading.

Bake for 18–20 minutes, or until the edges are golden brown and the center is slightly underbaked (it will set as it cools).

Remove the cookie from the oven and immediately sprinkle your desired toppings (e.g., chocolate chips, marshmallows) while it's still warm. The residual heat will melt the toppings slightly, helping them stick.

Let the pizza cookie cool in the pan for about 10 minutes before transferring it to a wire rack. Once completely cooled, slice it into wedges like a pizza and serve.