This berry powerhouse of a dessert is a meringue-filled wonder.
Preheat oven to 200 degrees. Trace two 6-inch circles onto a piece of parchment paper. Turn over and use paper to line a baking sheet.
In a large bowl, using an electric mixer, beat egg whites and cream of tartar on high until soft peaks form, about 2 minutes. Beat in 1/4 cup sugar. With mixer running, add 1/4 cup sugar, 1 tablespoon at a time. Stop mixer and scrape down bowl. Continue to beat on high until whites are very stiff and glossy, and sugar has almost completely dissolved, about 5 minutes. Beat in vanilla extract.
Gently shape 2 rounds of meringue on sheet, using circles as a guide. Smooth tops. Bake until meringues are crispy on the outside and detach easily from paper, about 1 1/2 hours, rotating sheet halfway through. Turn oven off and let meringues cool completely in oven. Gently peel from paper and place on serving plates; top each with 1 cup whipped heavy cream, 2/3 cup raspberry or lemon curd, and 1 1/2 cups mixed berries tossed with 1 tablespoon sugar.
If you wish, you can substitute Easy Lemon Curd for the Raspberry Curd.