For the sponge, place the flour in a small bowl. Measure warm tap water and whisk the yeast into the water. Stir the yeast mixture into the flour. Cover tightly with plastic wrap and allow to ferment at room temperature until double, about 30 minutes.
For the dough, place the ingredients in the order given in the bowl of a heavy-duty mixer fitted with the paddle or in a mixing bowl. Add the sponge and beat on the lowest speed. This should take about 5 minutes by machine. If you are mixing by hand, use your hand to squeeze the dough together, then turn the dough out onto a lightly floured surface and knead it by folding it over on itself repeatedly until smooth and elastic, about 10 minutes.
Add the raisins, candied peel, pine nuts, and fennel seeds to the dough and mix in gently, by machine or by hand. Cover the bowl and allow to ferment until double, about 3 to 4 hours.
Scrape the dough out onto a floured surface and fold it over on itself several times to deflate. Form the dough into a round loaf, place it on a parchment-lined cookie sheet, and cover with a towel. Allow to proof until double, about 2 to 3 hours.
Immediately before baking, slash the top of the pandolce: make 2 parallel cuts
Bake the pandolce at 375 degrees for about 1 hour until well risen and a deep golden color, and until a thin knife blade inserted into the thickest part emerges clean.
Cool the pandolce on a rack. Store well wrapped in plastic at room temperature.
© 1990 Nick Malgieri. All rights reserved.