Photo: Ditte Isager

At Tina Casceli's Milk & Cookies Bakery in New York City, customers can design their own dreamed up flavors—say, marshmallow-white chocolate-macadamia cookies—which get baked fresh on the spot. Here, Casceli shares a basic dough recipe from her cookbook, Milk & Cookies, out this month. Prep the dough before the party, then use it as the base for the combinations she suggests, or anything else you and your friends can imagine.



Makes about 3 dozen cookies

Ingredients

• 2 1/2 cups old-fashioned rolled oats, or 2 cups oatmeal flour
• 2 cups all-purpose flour
• 1 tsp. baking powder
• 1 tsp. baking soda
• 1/2 tsp. salt
• 1 1/2 cups (3 sticks) unsalted butter, at room temperature
• 1 cup granulated sugar
• 1 cup light brown sugar
• 2 large eggs, at room temperature
• 1 1/2 Tbsp. vanilla extract

Candy: Chocolate chips, white chocolate chips or chunks, bittersweet chocolate shavings, caramel chips, M&Ms, chocolate-covered pretzels, broken candy bars, marshmallows, peppermints

Nuts: Chopped macadamia nuts, pecans, almonds, peanuts, and walnuts; peanut butter, coconut flakes

Fruits: Dried candied pineapple, dried papaya, dried blueberries, dried cranberries, candied ginger, golden raisins, dried apricots

Other: Cinnamon, cardamom, maple syrup, sanding sugar, walnut or orange liqueur, coffee extract, peppermint extract, jam, citrus zests, almond paste, sea salt, cream cheese

Directions

Active time: 30 minutes
Total time: 1 hour

Place oats in the bowl of a food processor fitted with metal blade and process until finely ground. (Or use ground oat flour and skip this step.) Transfer the ground oats to a large mixing bowl and add in flour, baking powder, baking soda, and salt. Set aside.

Put the butter in the bowl of a standing electric mixer fitted with the paddle. Beat on low speed until soft, then increase speed to medium and beat until light and creamy, about 3 minutes. Gradually add granulated sugar and then brown sugar, beating until very light and creamy.

Add eggs, 1 at a time, and beat to incorporate, scraping down the sides of the bowl with a rubber spatula after each addition. Beat in the vanilla and when blended, slowly beat in the reserved dry mixture. Stop while the dough is still streaky, and scrape it out onto a floured surface. Divide dough into 2 sections and gently knead each with your hands until just blended. Wrap in plastic wrap and refrigerate for at least 30 minutes, and up to 3 days (or freeze for up to a month). Take out 10 minutes before ready to bake.

To assemble and bake: Preheat the oven to 350°. Cover 2 baking sheets with parchment paper or silicone mats. For each cookie, take about a 1 1/2-inch ball of dough and knead in toppings as desired. For nuts, fruits, and candy, add what you like as long as there's enough dough to bind together the ingredients. For intensely flavored add-ins, like extracts, zests, salts, and spices, use a very small pinch, less than 1/8 tsp. (See combination suggestions, right.)

Place cookies evenly on prepared sheets, giving each enough room to spread. Bake until center sets and cookies are lightly golden, 12 to 15 minutes.

Cookie Combinations

Walnut: Walnut liqueur + walnuts
Mint chocolate chip: Peppermint extract + chocolate chips
Mocha: Coffee extract + milk chocolate
Spice: Ginger + cloves + nutmeg + cardamom + cinnamon
Tropical: Papaya + coconut + macadamia nuts
Snickerdoodle: Cinnamon + sanding sugar
Ginger Snap: Ginger + cinnamon + clove
Chocolate-Caramel: Chocolate chips + caramel
Chocolate-Orange: Grand Marnier liqueur+ grated orange zest + chocolate chunks + pecans
Macadamia: White chocolate chips + chopped macadamia nuts
Fruit and Nut: White chocolate chips + dried cherries + pecans
Candy Bar: Bittersweet chocolate chunks + toffee bits
Chocolate-Almond: Milk chocolate chunks + sliced almonds
Chocolate-Coconut: Chocolate chips + coconut flakes

Vanilla dough recipe adapted from Milk & Cookies by Tina Casceli (Chronicle Books).