Marshmallow PEEPS Cookie Sandwiches

INGREDIENTS

3/4 cup

or 170g) unsalted butter, softened to room temperature

3/4 cup

packed dark brown sugar (or light brown)

1/4 cup

granulated sugar

large egg, at room temperature*

2 tsp

vanilla extract

2 cups

all-purpose flour (measured correctly)

2 tsp

cornstarch

1 tsp

baking soda

1/2 tsp

salt

and 1/4 cups (250g) peanut butter M&Ms (or regular M&Ms, peanut M&Ms, chocolate chips)

1/2 cup

sprinkles

PEEPS marshmallow candies