Beat the butter with 100 grams of sugar in the mixer at medium speed until the two ingredients are integrated.
Meanwhile, separate the egg whites from the yolks, and beat the egg whites until stiff peaks form. When they begin to foam, gradually incorporate the remaining 100 grams of sugar.
Next, add the beaten egg whites to the previous batter and mix them in with gentle movements.
Combine and sift the flour with the salt and baking powder.
Then, add this flour, the Irish cream, and the remaining flour in that order, beating at a low speed between each addition.
Now, divide half of the batter in two, and to one of them add the cocoa and mix.
Before baking, grease the mold with butter and dust it with flour to prevent the batter from sticking. To achieve the marbled effect, pour the two batters in different batches. For example, I usually pour half of the batter without cocoa into the mold, then all the batter with cocoa, and finally, I pour the rest of the batter without cocoa. For a greater effect, you can mix the batters to your liking using a fork.
Finally, preheat to 180ÂșC with heat from both above and below for 50 minutes and let it cool before serving.