Line a baking tray with lightly greased parchment paper.
Place warm milk, water, sugar, in a small mixing cup and mix to dissolve sugar. Add yeast and stir until completely dissolved. Let mixture stand until yeast begins to foam vigorously, about 5 – 10 minutes.
Add flour and salt into the bowl of a stand mixer fitted with the hook (bread paddle) attachment. Make a well in the center and add the yeast mixture, egg and butter to the well; mix on medium speed until incorporated. Increase the speed to medium-high and mix until the dough forms a ball and pulls away from the sides of the bowl, about 8 - 10 minutes. The dough should be elastic but not sticky, if too sticky add a little more flour, about a tablespoon at the time.
Place the dough on a lightly floured surface and form a ball. Place the dough in a lightly greased bowl, cover, and let it rise for 60 minutes until it's nearly doubled in bulk.
Then, place the dough on a lightly floured surface and roll it into r 15"L x 13"W rectangle, about ½ inch thick.
Arrange a row of whole olives on the upper edge. Slice the rest of the olives.
Line the dough with the ham slices, slightly overlapping each piece and covering the entire surface of the dough.
Sprinkle the raisins and sliced olives on top of the ham, scattering them evenly throughout. Drizzle with papelon syrup, if using.
Firmly roll it up like a Swiss roll. Transfer the roll, seam-side down, to the prepared baking sheet. Put a warm damp towel, loosely on top of the bread, place it in a warm and humid area in your kitchen and let it sit for 60 minutes.
Preheat oven to 350º F.
Brush bread with egg wash for all sides. Bake for 40 – 45 minutes, or until golden brown. Remove the bread from the oven, and while is still hot brush with melted butter.
Let the bread cool for 15 – 20 minutes before serving.