Start by removing the crust from the bread until you have 300 g of crumb.
Cut the crumb into small pieces and place them in a bowl.
Soak the bread in milk for about 10 minutes, stirring it after 5 minutes to ensure even absorption.
While the bread soaks, place the raisins in a bowl and cover them with water to plump them up. Let them sit for about 5 minutes.
Grate the lemon zest and set it aside.
Grease a 22 cm (9-inch) cake tin with a bit of butter and dust it with breadcrumbs to prevent sticking. Preheat your oven to 180 °C (356 °F).
After the bread has soaked, squeeze it to remove excess milk.
Combine the soaked bread with sugar, egg, and softened butter in a large mixing bowl. Use a wooden spoon to mix everything until well combined.
Add the grappa, drained raisins, lemon zest, and pine nuts to the bread mixture.
Sift in the flour and mix thoroughly until you have a compact, homogeneous batter.
Transfer the mixture into the prepared cake tin, smoothing the top with a spoon.
Bake in the preheated oven for about 60 minutes, or until the top is golden, and a toothpick inserted into the center comes out clean.
Once baked, remove the cake from the oven and let it cool completely before serving.