Grind tapioca in a blender or coffee grinder until it is a fine granular powder.
Whisk milk (or soymilk), maple syrup, egg and the tapioca in a small heavy saucepan. Cook over medium-high heat, whisking constantly, until the mixture comes to a full boil. Remove from the heat, stir in vanilla and transfer to a medium bowl. Place plastic wrap directly on the surface. Refrigerate until chilled, about 3 hours or overnight.
Whip cream using an electric mixer or whisk in a chilled bowl until soft peaks form. Fold the whipped cream into the tapioca mixture using a rubber spatula.
Spoon 1/4 cup strawberries into each of six 8-ounce parfait glasses or wineglasses. Top each with 1/3 cup tapioca cream. Repeat with another layer of strawberries and tapioca cream. Garnish with the remaining berries and a sprig of mint.