Chewy Chocolate Chip Cookie Cake Recipe with Buttercream Border

This cookie cake recipe gives you a golden-brown, chewy round loaded with melty chocolate in just 35 minutes. There's no dough chilling and no fuss, so it's perfect for birthdays, potlucks or midnight cravings.

An extra egg yolk and a pinch of cornstarch keep every slice soft and chewy. Pulling the pan while the center still looks pale guarantees a gooey, tender middle.

Ingredients You'll Need

Unsalted Butter: Soft, creamy butter is the backbone of both the cookie cake and the buttercream border. Softened butter traps air when you beat it, so the dough bakes up tender. If you only have salted butter, use it and cut the kosher salt in half.

Light Brown Sugar: Packed brown sugar brings deep caramel notes and molasses moisture. That moisture is what makes each slice bend instead of snap. Dark brown sugar works too and gives a richer, toffee-like flavor.

Granulated Sugar: Plain white sugar crisps up those golden-brown edges we all fight over. It also helps the butter whip pale and fluffy. Caster sugar is a fine swap and dissolves even faster.

Egg: One large room-temperature egg binds the dough and gives it lift. Cold eggs can make the butter seize and curdle. In a pinch, use 3 tablespoons of whisked egg from a carton.

Egg Yolk: The extra yolk adds richness and that dense, chewy bite. It makes the center taste almost like raw cookie dough, in the best way. Swap in 1 tablespoon of heavy cream if you're out of eggs.

Pure Vanilla Extract: Vanilla goes into the dough and the buttercream, and it makes the whole kitchen smell fragrant and warm. It rounds out the sugar so the sweetness tastes cozy, not flat. Vanilla bean paste is a lovely upgrade with pretty speckles.

All-Purpose Flour: Flour gives the cookie cake its structure so it slices cleanly. Spoon and level it, because packing it in makes a dry, cakey round. Bread flour gives an even chewier slice if that's what you have.

Cornstarch: Just one teaspoon keeps the crumb soft and tender. It softens the flour's gluten so the middle stays plush for days. Arrowroot powder works the same way.

Baking Soda: Baking soda helps the dough spread and rise into an even, golden round. It also deepens the browning on top. Swap in 3 teaspoons of baking powder, though the cake will be a little puffier.

Kosher Salt: Salt makes the chocolate taste more chocolatey and tames all that sugar. Kosher flakes are gentler than table salt. Use ¼ teaspoon of fine sea salt instead.

Semisweet Chocolate Chips: These are the melty pockets of joy in every bite. Semisweet balances the sweet dough with a little bitterness. Chopped dark chocolate bars or milk chocolate chips both work beautifully.

Powdered Sugar: Sifted powdered sugar whips into a silky, lump-free buttercream. Its fine texture is what lets the border hold stiff, ruffled peaks. Blitz granulated sugar in a blender until powdery if you run out.

Whole Milk: One splash of milk loosens the buttercream so it pipes smoothly. Whole milk keeps it rich and creamy. Heavy cream makes it even fluffier, and oat milk works for dairy-light frosting.

How to Make It (Step by Step)

It all happens in one bowl and one round pan: cream, stir, press, bake golden-brown, then pipe a fluffy border.

Even if you've never piped buttercream before, this cookie cake comes out chewy, gorgeous and party-ready.

1. Whisk the flour, cornstarch, baking soda and kosher salt in a medium bowl until evenly blended with no streaks, about 30 seconds at room temperature (70°F / 21°C). Meanwhile, preheat the oven to 350°F / 175°C and line a 12-inch round pan with parchment.

2. Beat the softened butter, light brown sugar and granulated sugar on medium speed until pale, fluffy and nearly doubled, 2-3 minutes at room temperature (70°F / 21°C). Scrape the bowl once. Grandma never skipped that scrape.

3. Beat in the egg, egg yolk and vanilla until the mixture turns smooth, glossy and creamy, about 1 minute at room temperature (70°F / 21°C). Room-temperature eggs blend in without curdling.

4. Mix in the flour mixture on low speed until a soft, thick dough forms with no dry patches, 30-45 seconds at room temperature (70°F / 21°C). Stop the moment the flour disappears.

5. Fold in the semisweet chocolate chips with a rubber spatula until they're scattered through every bite, about 30 seconds at room temperature (70°F / 21°C). Sneak one spoonful. She'd have pretended not to notice.

6. Press the dough evenly into the parchment-lined 12-inch round pan until the surface is flat and level to the edges, about 2 minutes at room temperature (70°F / 21°C).

7. Bake until the edges are deep golden-brown and the center looks set but still soft, 18-22 minutes at 350°F / 175°C. A slightly pale middle means a chewy, gooey slice.

8. Cool the cookie cake in its pan on a wire rack until firm to the touch, about 1 hour at room temperature (70°F / 21°C). Warm cake melts buttercream fast.

9. Beat the softened butter, sifted powdered sugar, whole milk and vanilla until the buttercream is silky, fluffy and holds stiff peaks, 2-3 minutes at room temperature (70°F / 21°C).

10. Pipe the buttercream in a ruffled border around the cooled cake's edge until the rim is fully framed, 3-5 minutes at room temperature (70°F / 21°C). Slice, share, and save one for midnight.

Chill leftovers up to 5 days or freeze unfrosted slices 3 months, warming 10 seconds to revive the gooey middle. Swap dark brown sugar for light, press dough a day ahead, and spoon-and-level your flour.

Serving size: 1 portion · Calories: 540 · Total Fat: 30g · Saturated Fat: 19g · Carbs: 67g · Fiber: 2g · Sugar: 48g · Protein: 5g · Sodium: 185mg

Tips and Tricks

• Equipment: Use a light-colored 12-inch round metal pan lined with parchment. A light metal pan heats evenly, so the edges turn golden-brown without scorching. The parchment lets the whole cake lift out in one piece. Grandma swore by her old dented one, and I still use it.

• Temperature precision: Trust an oven thermometer, not the dial. Many ovens run 15-25 degrees hot or cold. Hang a cheap thermometer inside and make sure it reads a true 350°F / 175°C before the pan goes in. Just a few extra degrees can turn a chewy middle dry and crumbly.
• Common mistake: Don't keep mixing once the flour disappears. Overbeating the dough builds gluten, and your soft cookie cake turns tough and bready. Switch to low speed and stop the second the dry streaks vanish. Let the rubber spatula handle the chocolate chips gently.
• Flavour upgrade: Whisk 1 teaspoon of instant espresso powder into the flour. It won't make the cake taste like coffee. It deepens the semisweet chocolate and makes the brown sugar taste rich and toffee-like. It's my little midnight secret.
• Texture tip: Pull it while the center still looks a touch underdone. You want deep golden-brown edges with a center that looks set but slightly pale. The cake keeps baking in the hot pan as it cools, so you get crisp edges and a fudgy, gooey middle.

Frequently Asked Questions

Can I make this cookie cake recipe gluten-free or dairy-free without ruining the texture?

Use 2¼ cups (281 g) measure-for-measure gluten-free flour with xanthan gum, and swap the butter for 1 cup (226 g) vegan butter sticks plus dairy-free chocolate chips. For the border, use ½ cup (113 g) vegan butter and 1 tablespoon oat milk.

Can I bake the cookie cake and buttercream days before a party?

Bake the unfrosted cake up to 2 days ahead, wrapped airtight at room temperature, and refrigerate the buttercream separately up to 1 week or freeze it 3 months. Refresh the cake for 5 minutes at 300°F / 150°C, cool it, then re-whip the softened buttercream and pipe.

Why did my cookie cake come out dry and crumbly instead of chewy?

It was likely overbaked or packed with too much flour, so pull it at 18 minutes when the edges are deep golden-brown but the center still looks slightly pale and soft. Stop mixing the moment the flour disappears, since overworked dough bakes up tough.

What to Serve With This

• Lemon-Macerated Strawberries: Juicy, tart berries cut through the buttery, caramel-sweet chew of every chocolate-studded slice.
• Tangy Lemon Greek Yogurt: A cool, velvety spoonful adds bright acidity that balances the rich vanilla buttercream border.
• Raspberry Sorbet: Icy, sharp, and fruity, it melts beside the warm, gooey center like a little celebration.
• Fresh Orange and Grapefruit Segments: Zesty, juicy citrus refreshes your palate between bites of deep golden-brown cookie edge.