INGREDIENTS
1
frozen pie crust (see pie crust recipe for instructions to make your own)
3 1/2
to 4 cups chopped rhubarb stalks (about 1 lb)
3/4 cup
white granulated sugar
1 tbsp
orange zest
1/4 tsp
cinnamon
1/4 tsp
ground ginger
3 tbsp
instant tapioca or 2 Tbsp tapioca flour/starch (can sub 2 Tbsp corn starch)
1 tbsp
cornstarch
1/3 cup
cold water
1/4 tsp
cream of tartar (can use vinegar instead of cream of tartar, see method instructions)
1/2 cup
white granulated sugar
4
large egg whites (room temperature)
1/2 tsp
vanilla extract