Preheat oven to 190 degrees C and grease a 6-cup muffin tin or line with patty cups.
In a bowl, sift together the flour, baking powder and salt. In a separate bowl, beat the eggs, milk and melted butter until combined.
Drain the pineapple pieces and dice them fairly small. Dice the prosciutto and sun-dried tomatoes, and slice the olives into rings.
Add the pineapple, prosciutto, tomatoes and olives to the wet ingredients and mix well. Add the oregano and grated cheese and mix. Add the wet ingredients to the dry and stir to make a mostly smooth batter, don't over mix.
Fill the muffin cups 3/4 of the way full and bake for 25-30 minutes. If you like, sprinkle a little extra cheese on top for the last 5 minutes of baking.