Homemade Fudge Rounds

INGREDIENTS

For the cookies::

1 cup

all-purpose flour

1 tsp

cornstarch

1/4 cup

plus 2 tablespoons unsweetened cocoa powder

1/2 tsp

baking soda

1/4 tsp

fine salt

10 tbsp

unsalted butter, at room temperature

3/4 cup

granulated sugar

large egg

1 tbsp

corn syrup

1 tsp

vanilla

For the filling::

1 stick

unsalted butter, at room temperature

1/2 tsp

vanilla

2 tbsp

cocoa powder, sifted

1 1/2 cups

powdered sugar, sifted

2 tbsp

warm water

For the chocolate stripes::

1/2 cup

milk chocolate chips

1 tsp

vegetable oil