Prepare the pizza oven or grill for baking pizza at (see our online guide for perfect pizza on the grill).
Combine the crème fraiche and mascarpone cheese.
Roll out the pizza dough to about 14″ and transfer to a pizza prep peel lightly dusted with corn meal. Spread on the crème fraîche mixture. Drizzle with honey. Sprinkle with salt. Break up the raspberries and blackberries, removing and discarding the cores from the blackberries. Distribute all the berries evenly across the pizza.
Bake the pizza until the crust is golden brown and the toppings are hot. At 500 degrees it should take about 10 minutes. At 750 degrees it will take only about 3 minutes.
Garnish with mint leaves before serving.
