from: gimme some oven
2 2/3 cups all-purpose flour
1 teaspoon baking powder
1 teaspoon baking soda
1 teaspoon cornstarch
1 teaspoon salt
1 cup (2 sticks) butter, softened
1 cup granulated sugar
1 cup packed light brown sugar
1 cup peanut butter (smooth or crunchy)
2 teaspoons vanilla extract
2 large eggs
(optional: 1/2 cup granulated sugar for rolling the dough balls)
INSTRUCTIONS
Preheat oven to 350˚F. Line a baking sheet with parchment paper; set aside.
Whisk together flour, baking powder, baking soda, cornstarch and salt in a large bowl and set aside.
In an electric mixer fitted with the paddle attachment, beat together the softened butter, granulated sugar and brown sugar on medium speed until light and fluffy (about 3 minutes). Mix in peanut butter until it is incorporated and smooth. Add vanilla and eggs, one at a time, scraping the bowl down after each addition. Reduce mixer speed to low and slowly add dry ingredients until they are just incorporated and the batter is smooth, being careful not to over-mix.
Form the dough into 1.5-tablespoon round balls and place on the prepared baking sheet. (If you’d like, you can roll each of these balls in a bowl of granulated sugar before adding them to the baking sheet.) Press a criss-cross pattern into each dough ball with a fork to flatten, being sure that each dough ball is at least 2 inches apart. Bake for 10-12 minutes, until the edges are golden brown and the centers are slightly puffy. Remove from the oven, and then transfer the cookies to a cooling rack to cool.
Serve warm, or store in a sealed container for up to 4 days. Or freeze for up to 3 months.