Molten White Chocolate Matcha Skillet Lava Cookie Step-by-step instructions

Before you start

Before starting, make the lava center: melt the white chocolate with cream, pour into a small dish, and freeze until firm, at least 1 hour. This can be done a day ahead. Then, gather all the cookie dough ingredients and let the egg come to room temperature if possible.

Preheat the oven to 350°F (175°C) and butter a 6-inch cast iron skillet. Have a whisk, a mixing bowl, and a rubber spatula ready. The entire process is quick, so having everything measured and ready will make assembly seamless.

Instructions

Prep and assemble

1. 1Make the lava center
   In a small saucepan over low heat, melt 80 g white chocolate with 2 tbsp heavy cream, stirring constantly until smooth. Pour the ganache into a small freezer-safe dish lined with plastic wrap, forming a disk about 2 inches wide. Freeze for at least 1 hour, until firm.
   Look for The ganache should be thick and set, not liquid.
   Tip Freeze the ganache disk while you prepare the cookie dough.
2. 2Mix the cookie dough
   In a mixing bowl, whisk the melted butter and sugar until combined. Add the egg and whisk until smooth and slightly pale. Sift in the flour, matcha powder, and baking powder, then fold with a spatula until a soft green dough forms. Stir in the white chocolate chips.
   Look for The dough should be cohesive and deeply green, with no dry flour streaks.
   Tip Sifting the matcha prevents lumps and ensures even color.
3. 3Assemble the skillet
   Butter a 6-inch cast iron skillet. Press half of the cookie dough evenly into the bottom. Place the frozen white chocolate ganache disk in the center, then top with the remaining dough, pressing the edges to seal completely, covering the ganache.
   Look for The ganache should be fully enclosed by dough.
   Tip Make sure the dough is thick enough at the edges to hold the lava in.

At this point, you should have a smooth, vibrant green cookie dough studded with white chocolate chips, and a frozen disk of white chocolate ganache. The dough should be soft but not sticky, and the ganache should be firm to the touch. The skillet is buttered and ready, and the oven is preheating. Everything is in place for a quick bake.

Bake until crisp-edged

4. 4Bake the skillet cookie
   Preheat the oven to 350°F (175°C). Bake the skillet cookie for 16 minutes, until the edges are golden and set, while the center remains soft and slightly underdone. The top should be matte, not shiny, and a toothpick inserted near the edge comes out clean but the center is still gooey.
   Look for The edges are crisp and the center still looks slightly soft and moist.
   Safe temperature 160°F (71°C) internal temperature (egg dishes)
   Tip Do not overbake, or the lava will set and you'll lose the molten effect.

The kitchen will smell of butter and matcha, and the skillet will be sizzling gently. The edges of the cookie are golden and crisp, while the center still looks slightly pale and soft. The top is matte, and a toothpick inserted near the edge comes out clean. The center should be slightly puffed but will settle as it cools.

Top and crack open

5. 5Top and serve
   Let the skillet cookie cool for 2 minutes, then place a generous scoop of matcha ice cream on top. Using a spoon, crack open the center to reveal the molten white chocolate lava. Serve immediately, scooping the warm cookie with the cold ice cream.
   Look for The lava should flow out slowly and mix with the melting ice cream.
   Tip Warm the spoon slightly to help crack the cookie cleanly.

The skillet cookie is warm, the matcha ice cream is melting over the top, and when you crack the center with a spoon, a river of molten white chocolate flows out, mixing with the green ice cream. The contrast of hot and cold, crisp and gooey, is exactly what you want. Serve immediately, scooping up every bit of the lava.

Common mistakes

The most common mistake is overbaking, which causes the lava center to set and lose its molten quality. Watch the cookie closely in the final minutes; the center should still look slightly soft and underdone when you pull it out.

Another mistake is not sealing the dough around the ganache, which can cause the lava to leak out during baking.

Press the top dough firmly to the edges and make sure there are no gaps. Also, don't skip freezing the ganache—if it's not frozen solid, it will melt and spread into the dough instead of staying as a distinct molten core.

How to tell it’s done

The skillet cookie is done when the edges are golden brown and set, and the top is matte, not shiny. A toothpick inserted near the edge should come out with a few moist crumbs, but the center should still feel soft and slightly underdone—this is where the lava will be.

The internal temperature of the cookie should reach at least 160°F (71°C) to ensure the egg is fully cooked. Let it rest for 2 minutes before serving, which allows the lava to set slightly and prevents it from running out too quickly.

• Egg dishes: 160°F (71°C) in the thickest part