INGREDIENTS
1
Egg, large
2 1/4 cups
Oats, old-fashioned
1/2 tsp
Baking powder
1 cup
Bittersweet chocolate
1/3 cup
Brown sugar, packed light
1 tbsp
Cornstarch
1/3 cup
Granulated sugar
1/2 tsp
Kosher or sea salt
1 tsp
Vanilla extract, pure
1/2 cup
Butter, unsalted
1
Parchment paper