Preheat oven to 425°F.
Combine 1 cup flour, undissolved yeast, brown sugar, salt and cinnamon in a large bowl. Add very warm milk and butter; mix until well blended, about 1 minute.
Gradually add enough remaining flour to make a soft dough. Dough should form a ball and will be slightly sticky. Knead** on a floured surface, adding additional flour if necessary, until smooth and elastic, about 4 minutes.
Pat dough with floured hands to fill greased pizza pan or baking sheet. OR roll dough on a floured counter to 13-inch rectangle; place in greased pizza pan or baking sheet. Form a rim by pinching the edge of the dough; prick surface with a fork.
Bake on lowest oven rack 10 to 12 minutes or until crust is lightly browned. Slide crust out of pan onto wire rack and cool completely.
Mix crème fraiche, powdered sugar, and vanilla extract at medium speed for 2 to 3 minutes until light. Spread mixture over pizza crust. Top with berries, kiwi and mandarin oranges in rainbow color order(red, orange, green, blue). Chill pizza until ready to serve.
*If you don’t have a thermometer, water should feel very warm to the touch.
**To knead the dough, add just enough flour to the dough and your hands to keep the dough from sticking. Flatten dough and fold it toward you.Using the heels of your hands, push the dough away with a rolling motion. Rotate dough a quarter turn and repeat the “fold, push and turn” steps. Keep kneading dough until it is smooth and elastic. Use a little more flour if dough becomes too sticky, always working the flour into the ball of dough.