Lemon Ice Cream Sandwiches with Blueberry Swirl

INGREDIENTS

2 cups

Blueberries

1 tbsp

Lemon, zest

Egg, large

3 tbsp

Lemon juice, fresh

1 cup

All-purpose flour

1/2 tsp

Baking powder

1/4 tsp

Baking soda

3/4 cup

Brown sugar, packed light

2 tsp

Cornstarch

1/4 tsp

Salt

1/4 cup

Sugar

1/2 tsp

Vanilla extract, pure

1 stick

Butter, unsalted

2 pints

Premium vanilla ice cream

2 (3-by 2 1/2-inch) strips lemon zest