Allow the egg whites to sit at room temperature for at least 30 minutes.
Preheat your oven to 350°F (175°C). Line two standard muffin pans with paper baking cups.
In a food processor or blender, process the gluten-free flour, cornstarch, and powdered sugar until well combined.
In a large bowl, beat the egg whites with cream of tartar and salt until soft peaks form. Gradually add granulated sugar and beat until stiff, glossy peaks form.
Gently fold the dry ingredients and vanilla/almond extracts into the egg whites until just combined. Carefully spoon the batter into prepared cupcake liners, filling each ⅔ full.
Bake for 15-18 minutes, until the cupcakes are lightly golden and spring back when touched. Cool completely on a wire rack.
For the mascarpone whipped cream: In a bowl, whisk mascarpone, powdered sugar, E-Z Gel, and extracts until smooth. Whip the heavy cream until soft peaks form, then gently fold into the mascarpone mixture.
Fill a piping bag with the whipped cream and frost the cooled cupcakes. Top with fresh berries before serving.