Line a cookie sheet with parchment paper, then scoop the dough into 1 tablespoon-sized balls and place them on the pan. Use your thumb or a rounded surface, like the bottom of a wooden spoon, to make an indentation in the center of each cookie. Transfer the cookie sheet to the freezer for 15 minutes “so that cookies hold their shape better while they bake,” Morone explains. In fact, if you want to make these well ahead of time, you can leave the unbaked cookies in the freezer (wrapped) for up to 3 months.
While the cookie dough chills, preheat the oven to 350 F. Once hot, bake the cookies for 12-15 minutes until the edges are golden brown. However, at about the 7- to 10-minute mark, you’ll want to remove the baking sheet and check to see if the cookies have puffed up in the center. “Without a filling in the center of a thumbprint cookie, the centers can puff up,” Morone says. Don’t worry if they look a bit puffy — just push the center back down with the top handle of a wooden spoon, then continue baking. When the cookies are done, remove the tray from the oven and let them cool completely.