Preheat oven to 350° F. Line a baking sheet with parchment paper. Draw an 8-10 inch circle on the parchment paper. This will be the guide for your meringue wreath. Flip the paper over so the pencil side is down. You will still be able to see the guide on the other side.
Place the egg whites in the bowl of your mixer, along with the cream of tartar. Beat until frothy and foamy. Slowly add sugar, and continue to beat on high until you have very stiff, shiny peaks. You should be able to hold a spoon of the egg whites upside down and they will stay for a minute or so. Beat in vanilla.
Using a large spoon or a pastry bag fit with a large open star or plain tube tip, pipe the meringue around the circle by making large swirls or flowers with the bag or mounds if using a spoon, making the wreath about 3 inches wide. Fill in any gaps with extra meringue. The edges should be higher with little dips along the center of the wreath to hold cream and fruit.
Reduce the oven temp to 200°F. Place the meringue into the oven and bake for 90 minutes, rotating the pan halfway through the baking. After 90 minutes, the meringue should be crunchy on the outside, but remain soft on the inside. Remove from oven and allow it to cool to room temperature. Serve right away or store in an airtight container in a cool spot for a day or two, before serving.
Once cooled, fill the dips in the center of the wreath with yogurt-whipped cream, and arrange fruit on top. Refrigerate until ready to serve, but serve it soon, once the fruit is on top of the meringue it can get soggy.