Preheat the oven to 350 degrees F. Lightly grease a round 14-inch deep-dish pizza pan.
In a medium bowl, combine the butter and chocolate. Microwave on high, in 30-second intervals, stirring between each, until the chocolate is melted and smooth, about 1 minute 30 seconds total.
In a large bowl, beat the sugar and eggs at medium-high speed with an electric mixer until fluffy. Gradually beat in the flour and salt. Stir in the melted chocolate and vanilla extract. Pour the batter into the prepared pan, and bake until a toothpick inserted into the middle comes out clean, 16 to 18 minutes. Let cool completely.
Spread the softened ice cream evenly over the cooled brownie, to the edges of the pan. Freeze for 2 hours or up to 2 days.
Top the pizza with the caramel flavored ice cream topping, toasted coconut, cherries, hot fudge flavored topping, peanuts, pretzels, raspberries, strawberry flavored ice cream topping and whipped cream. Cut into wedges to serve.