Preheat your oven to 375°F (190°C) and line a baking dish with parchment paper. Melt the butter and chocolate chips together until smooth, then set it aside to cool. Combine all the dry ingredients in one bowl, while whisking eggs, sugar, vanilla, and sour cream in another. Slowly incorporate the melted chocolate and boiling water. Pour the batter into the baking dish, bake for 15-20 minutes, and allow it to cool. Crumble the cake gently with a fork.

Mix dulce de leche with milk until you get a silky, pourable consistency. This syrup will infuse the cake with rich caramel flavor while keeping it moist. If you’re a fan of desserts with luxurious fillings, you can also explore this Brie and Cranberry Tart for a completely different flavor profile.

Melt chocolate and butter together. Meanwhile, whisk egg yolks, sugar, and a splash of water in a saucepan over low heat until it thickens slightly. Combine this with the melted chocolate and refrigerate to cool. Whip heavy cream until peaks form, then gently fold it into the chilled chocolate mixture.

Start layering by spooning some dulce de leche syrup at the base of a jar. Add a layer of cake crumbles, drizzle more syrup, and top with chocolate mousse. Repeat the process until the jar is nearly full, then finish with a dollop of whipped cream, extra dulce de leche syrup, and a sprinkle of cake crumbs.

Refrigerate the jars for at least 2 hours before serving. This allows the layers to meld together beautifully. You can also enjoy similar indulgent creations featured in desserts that offer unique twists while keeping things decadent.