S’mores Lava Cake with Marshmallow Filling

Ingredients

Instructions

1. Preheat the oven to 350°F (175°C). Line three 8-inch cake pans with parchment paper and lightly grease.
2. Stir the espresso powder into the hot brewed coffee until dissolved. Set aside.
3. In a large bowl, whisk together the cake flour, granulated sugar, brown sugar, Dutch-process cocoa powder, natural cocoa powder, baking powder, baking soda, and salt.
4. In a separate bowl, combine the milk and apple cider vinegar and let stand for 2-3 minutes.
5. Add the oil, yogurt, and vanilla to the milk mixture and whisk until smooth.
6. Pour the wet ingredients into the dry ingredients and whisk just until combined.
7. Add the hot coffee mixture and whisk until the batter is smooth.
8. Divide the batter evenly among the prepared pans.
9. Bake for 22-25 minutes, or until the centers spring back when lightly touched and a tester comes out with moist crumbs.
10. Cool the layers in the pans for 15 minutes, then transfer them to wire racks to cool completely.
11. Make the Golden Oreo crunch. Melt the butter in a pan over medium heat. Add the crushed Golden Oreos, granulated sugar, brown sugar, and salt.
12. Cook, stirring constantly, until the mixture looks dry, lightly golden, and forms crisp clusters. Continue cooking for 1-2 minutes, until lightly toasted and no longer greasy.
13. Spread the crunch in a thin layer on parchment paper and cool completely.
14. Make the marshmallow lava. Whisk the marshmallow fluff, salt, and vanilla bean paste until smooth.
15. Slowly stream in the warm cream while whisking continuously until glossy and fluid. Whisk in the melted butter until fully incorporated.
16. Let the marshmallow lava cool completely to room temperature before assembly. It should thicken slightly while remaining pourable.
17. Make the chocolate buttercream. Beat the room-temperature butter until smooth and creamy.
18. Add both cocoa powders, the salt, and vanilla bean paste. Beat until completely smooth with no dry pockets.
19. Add the powdered sugar in 2-3 additions, mixing on low until incorporated. Increase the speed and mix until fluffy.
20. Slowly stream in the cream until the buttercream is silky, light, and spreadable. Beat for 2-3 minutes, until smooth and aerated.
21. Place the first cake layer on a serving board or cake stand. Spread on a thin layer of buttercream, then pipe a tall, continuous buttercream dam around the edge.
22. Reserve a little marshmallow lava and Golden Oreo crunch for the top. Scatter cooled crunch inside the buttercream dam, then pour in half of the remaining room-temperature marshmallow lava. Keep the filling below halfway up the dam.
23. Add the second cake layer and repeat with a thin buttercream layer, a tall dam, cooled crunch, and the remaining filling, keeping the reserved topping aside.
24. Top with the final cake layer and frost with chocolate buttercream. Finish with the reserved marshmallow lava and Golden Oreo crunch, then add marshmallows. Toast the marshmallows carefully with a kitchen torch, or toast them separately under a closely watched broiler before placing them on the cake. Do not put the frosted cake under the broiler. Chill briefly until the buttercream is steady, then let the cake soften slightly before slicing.

Helpful notes

• Use the marshmallow lava at room temperature and keep it below halfway up a tall buttercream dam.
• Reserve a little marshmallow lava and Golden Oreo crunch for decorating before filling the cake layers.