Stir together the raisins, dried currants, chopped peel, sliced almonds, and orange juice until well mixed. Leave to soak while you make the bread dough.
Pour the flour into a large bowl, adding the yeast and salt on opposite sides of the bowl. Stir in each one with your finger. Mix in the sugar.
Dump in the warmed milk, orange zest, vanilla, and egg, and bring the mix together with your hand. The dough may be dry at this stage, but don't add any additional liquid to it.
Cover the dough with plastic wrap and let it prove at room temperature for 40 minutes.
Put the butter in a saucepan set over low heat until melted.
Gradually add the melted butter to the dough, squeezing and crushing the dough with your hand to incorporate. Once all of the butter is added, knead until all the butter is evenly distributed.
Cover the dough with plastic wrap again and let it prove for 1 hour.
Place the dough in the bowl of a stand mixer fitted with the paddle attachment. Add the soaked fruit mixture and mix on medium-low speed until evenly mixed. If you don't have a stand mixer, you can do this step by hand.
Let the dough rest for 30 minutes covered with plastic wrap.