1. Preheat your oven to 375 F (190 C). Lightly grease a 12-inch pizza pan or line it with parchment paper. Press the refrigerated sugar cookie dough evenly over the bottom of the pan, forming a circle. Ensure the dough is spread to the edges and has an even thickness for consistent baking.

2. Place the pizza pan in the preheated oven and bake for 12-15 minutes, or until the edges are lightly golden brown and the center is set. The cookie should look cooked through but still slightly soft. Remove from the oven and let it cool completely on a wire rack before proceeding. This step is crucial to prevent the frosting from melting.

3. While the cookie crust cools, prepare the frosting. In a medium bowl, beat the softened cream cheese with the granulated sugar and vanilla extract using an electric mixer on medium speed until the mixture is smooth and creamy, with no lumps.

4. Gently fold the thawed whipped topping into the cream cheese mixture using a spatula. Be careful not to overmix, as this can deflate the whipped topping. The goal is a light, airy, and uniform frosting. Cover the bowl and refrigerate the frosting for at least 30 minutes to allow it to firm up slightly, which makes it easier to spread.

5. Once the cookie crust is completely cool, spread the chilled cream cheese frosting evenly over the top, leaving about a 1/2-inch border around the edge. Use an offset spatula or the back of a spoon for smooth application.

6. Arrange the fresh blueberries and sliced strawberries on top of the frosting to create a festive design. For a classic flag look, you can place blueberries in a square in one corner and arrange strawberry slices in rows to mimic red stripes. Get creative with your pattern!

7. For best results and to allow the flavors to meld, refrigerate the fruit pizza for at least 30 minutes before serving. This also helps the frosting set and makes it easier to slice.

8. Once chilled, use a sharp knife or pizza cutter to slice the fruit pizza into wedges or squares. Serve immediately and enjoy your beautiful and delicious patriotic dessert!