Turn on the oven to preheat to 210 degrees. Cover a large baking sheet with parchment. In a bowl, combine 3/4 cup milk, butter, spinach, basil, tomatoes, and olives. In another, large bowl, combine flour, baking powder, and 1/2 teaspoon salt. Collect the flour mixture with a slide, make a depression in the center, and pour the milk mixture into it, stir well with a fork.
Pour the crumbly mass onto a floured surface and knead a homogeneous dough with your hands. Roll out the dough into a square, about 20×20 centimeters in size, cut it into 8 squares.
Place squares on a baking sheet, lightly grease with milk, sprinkle with crumbled cheese and pine nuts. Place the baking sheet in the oven and bake the bruschetta for about 15 minutes, until golden brown.