While preparing the dough, let the oven heat to 180 degrees.
In a mixer, beat the eggs with the sugar and butter. Then add the yogurt, flour and yeast. Beat until it becomes a homogeneous mass. Add the cocoa drops and mix with a spatula.
In a greased shape with butter and floured with cocoa powder, pour half of the dough. In the other half, add the cocoa powder, beat again and pour over the white mass.
I use a cone shape, put the black dough over the cone itself.
Place in the oven for 30 minutes.
You can slice and freeze. Do this, especially if you can't control yourself. The cake is not small, you can share and eat another day.