Preheat oven to 425°F Combine frozen berries, mascarpone, 2 tablespoons honey and lemon zest. Refrigerate until needed.
Using an electric mixer, beat egg whites with cornstarch, vanilla, lemon juice and salt at medium speed until stiff peaks form, 3-5 minutes. In small bowl, microwave 1/4 cup honey on high, until boiling, about 30 seconds.
While beating, slowly pour honey into egg whites. Increase speed to medium-high and beat until mixture is glossy and stiff, 5-8 minutes.
Place dessert shells on parchment paper-lined baking pan. Top each with a generous 1 tablespoons of mascarpone mixture.
Pipe or spread meringue over the top of the dessert shell and mascarpone mixture. Bake in preheated oven for 3-4 minutes, until golden brown.