Let the raisins soak in lukewarm water for 30 minutes, then pat dry with a paper towel.
In a standing mixer with a dough hook add starter dough, active dry yeast, water, sugar and flour. Mix on low speed until combined.
Add a pinch of salt, butter and an egg. Mix on medium speed for about 5 minutes until the dough becomes smooth and elastic.
Add raisins and aniseeds. Mix on low speed a few seconds until raisins and aniseeds spread evenly in the dough.
Transfer the dough to a clean bowl covered with a plastic wrap.
Let rise in dark warm (but not HOT) place until double in size (1-2 hours).
Past that time, line a baking sheet with parchment paper.
Turn the bowl with the dough upside down and gently helping with the hands let it “slide” down on the baking sheet.
Give it a round form and with your hands make a small hole in the center.
Place a glass or a cup to keep the hole during second proofing.
Let buccellato rise on a baking sheet for another 40-60 minutes.
Make sure to cover it with a lightly floured linen towel.
Remove the glass and bake buccellato in a preheated to 350F oven for 40-45 minutes.
Let cool and enjoy!