The sponge is done when it has risen and, when touched, the sponge falls. Add the egg yolks and the beer soaked in dried fruit to the sponge. Turn the mixer on low and let the liquids mix into the sponge. Then mix on medium speed for 2 – 3 minutes. Turn the mixer off, remove the paddle and replace it with a dough hook. In a separate bowl, sift together the flour, sugar and salt. With the mixer on low speed, gradually add the flour mixture to the sponge, until it is completely incorporated. The dough should be sticky to the touch. Let the mixer knead the dough for about 5 minutes, then let the dough rest for 5 – 10 minutes.