Preheat the oven for the dough (electric oven: 175 °C/circulating air: 150 °C/gas: see manufacturer). Wash organic oranges hot, dab dry and finely grate the peel. Squeeze oranges, measure 150 ml juice.
Cream 200 g soft butter, orange peel and sugar with the whisks of the mixer. Stir in the eggs one by one. Mix semolina, almonds, starch and baking powder. Stir 150 ml orange juice into the egg-sugar mixture.
Smooth the dough in the greased springform pan (20 cm Ø). Bake in the hot oven for about 1 hour (chopstick test). If necessary, cover with baking paper after about 40 minutes.
For the aperol oranges, meanwhile, peel the blood oranges so that the white skin is removed. Cut out fillets between the parting skins over a bowl. Squeeze the parting skins. Warm up the orange marmalade with aperol and 2-3 tablespoons of orange juice.
Add the orange filets. Remove from heat.
Take the cake out of the oven. Immediately prick the cake more often and sprinkle with approx. 5 tbsp. warm aperol jam. Leave to cool in the mould. Remove semolina cake from the tin. Serve with the rest of the aperol oranges.