1 Preheat oven to 350°F.2 In a medium bowl, whisk the flour, baking soda, and salt. Set aside.3 In the bowl of a stand mixer, at medium-low speed, mix the butter or margarine with the sugar and brown sugar. Raise the speed to medium-high and mix until creamy, light, and fluffy. Turn the speed down a little. Add the vanilla and eggs. Mix to incorporate.4 Add half the flour mixture. Mix. Add the remaining flour mixture and mix until just combined. Mix in the chocolate chips.5 Spray the aluminum tins with nonstick cooking spray.6 Fill each muffin cup or ramekin a quarter of the way with a large, ping-pong-ball-size ball of cookie dough. Flatten slightly to cover the bottom. Stack 2 chocolate squares in the center. Cover with a second walnut-sized ball of cookie dough, flattening it to completely cover the chocolate.7 Place onto a cookie sheet and bake until tops are golden brown. Do not overbake or the end result will be doughy, not gooey. The baking time will vary from 20–25 minutes depending on the size of the tin or ramekin and the amount of dough you needed to fill it.8 You are looking for the tops to be golden and not wet-looking. If using aluminum tins, turn each cookie out onto a plate. Serve warm.