First, preheat your oven to 350°F (175°C). While that’s warming up, grab a muffin tin and lightly grease it. This will ensure your cakes pop out easily after baking. You can also use silicone muffin molds for easy removal.

In a medium bowl, start by whisking together the cocoa powder, baking powder, flour, caster sugar, espresso powder, and sea salt. This helps to evenly distribute the leavening agent and ensures your cakes rise nicely.

Next, melt the butter and allow it to cool slightly. In a separate bowl, combine the melted butter, warmed milk, and vanilla extract. Stir well until everything is combined.

Gradually add the wet mixture to the dry ingredients. Stir until just combined. Avoid over-mixing; a few lumps are okay.

Spoon the batter into the prepared muffin tins, filling each cup about halfway. Don’t worry if it looks a bit thick; that’s how it should be.

In a separate bowl, combine the cocoa powder, light brown sugar, granulated sugar, and ground cinnamon. Stir these dry ingredients together. Next, pour in the freshly boiled water and mix until well combined. This sauce will create that luscious layer underneath the cake.

Carefully pour the pudding sauce over the batter you just placed in the muffin tins. It will seem like you’re doing it the wrong way, but trust me, it works out in the end. The sauce will sink to the bottom and create that amazing pudding effect as it bakes.

Place the muffin tin in the preheated oven. Bake for about 30 to 35 minutes, or until the tops are set and a toothpick inserted into the cake part comes out clean.

When they are done baking, let the cakes cool for a few minutes before digging in. This is often the hardest part, as the aroma will drive you wild. Once slightly cooled, you can serve them warm or at room temperature.