Unroll a pizza base and lay it on the baking paper on a baking tray. Cover the base with ham. Remove the cheese slices and place them on the ham. Unroll a second pizza base, place it on the cheese and remove the baking paper.
Press edges firmly together. Carefully scratch the top of the dough with a sharp knife. Drizzle with oil and sprinkle with some rosemary needles and sea salt. Bake in the preheated oven (electric cooker: 225 °C/ convection oven: 200 °C/ gas: level 4) for 15-20 minutes.
Cut the pizza into pieces and serve immediately.