Melt butter, set aside.
Whisk sugar and eggs till pale and fluffy, almost x3 the size in volume.
Mix a bit of the batter into the butter, then add that back into the mixture.
Then add the yogurt and vanilla.
Sift in the flour, salt, and baking powder and salt in 3 additions, careful not to overmix or deflate.
Separate the batter in half.
In a small bowl, mix the cocoa powder, rum and hot coffee, then add that to one half of batter.
In a greased and lined mold, alternate spoonfuls of each batter, then use a knife to swirl the batter.
Then I pipe a line of room temp butter down the middle, to make sure the cake rises properly and has a nice crack on the top. It's optional, but makes for a better looking bake!
Then bake in a preheated oven at 180C for 35-40 minutes until a toothpick inserted comes out clean.
For ganache on top, simmer 80 grams of cream, then pour over 80 grams of chopped chocolate. Leave for 5 minutes, then whisk to combine. Pour over cooled cake and smooth out.
