Preparation Steps

• Line two baking sheets with parchment and preheat the oven to 350°F (177°C).
• Make the chocolate center: Warm the cream in a small saucepan over medium heat just until steaming. Pour it over the chocolate chips in a heatproof bowl, cover, and let sit for 2 minutes. Stir until smooth and glossy, then set aside to thicken slightly while you prepare the cookies.
• Whisk the flour, baking powder, baking soda, and sea salt together in a medium bowl.
• In a large bowl with a hand mixer (or stand mixer), beat the softened butter and brown sugar on medium speed until light and fluffy, about 2 minutes. Beat in the egg and vanilla until fully combined, 30 seconds more.
• Add the dry ingredients to the butter mixture and mix on low just until a soft dough forms with no dry spots. Cover and chill the bowl for 15 minutes to help the cookies hold their shape.
• Scoop 1-tablespoon portions of dough (about 1-inch balls). Roll smooth and arrange 2 inches apart on the prepared baking sheets.
• Press a deep well in the center of each ball using your thumb or the back of a 1/2-teaspoon measuring spoon. Tip: Warm the spoon in hot water, dry it, and then press—this helps prevent cracking around the edges.
• Bake until the edges look set and just starting to turn golden, 9–10 minutes. If the centers puff, re-press the wells immediately after removing from the oven. Cool on the sheet for 5 minutes, then transfer to a rack to cool slightly.
• Stir the ganache again; it should be thick but spoonable. Spoon or pipe about 1 teaspoon into each indentation. Let the chocolate set for 20–30 minutes, or enjoy while the centers are still a bit warm and glossy.