Preheat oven to 325. Finely grind the gingersnaps in a food processor. Add butter and pulse to combine. Press into a 10” tart pan with a removable bottom and place in the preheated oven for 8-10 minutes. Cool completely.
Combine the mascarpone and cream cheese in a stand mixer. Beat until softened and combined.. Add the yogurt or sour cream, sugar, zest and vanilla. Beat until creamy, scraping down the sides to make sure all the ingredients are incorporated. Spread into the cooled crust and refrigerate for 2 hours.
Use a skewer or sharp knife to score a star pattern in the filling. This will make it easier to place the strawberries. Slice the strawberries and arrange in the star pattern on the tart. Fill in the space with the blueberries. Serve, or refrigerate for up to 8 hours. (Tart will keep for a day or longer, but the crust will soften.