Cream butter and sugar with the whisk of the hand mixer. Stir in the eggs one after the other. Mix flour, baking powder and salt, alternating with the milk. Peel and slice the bananas, marinate them with 2 tbsp. lemon juice and fold into the dough.
Line recesses of a muffin tray (12 recesses) with paper cups. Spread the dough into the paper cups. Bake the muffins in a preheated oven (electric cooker: 175 °C/ convection oven: 150 °C/ gas: see manufacturer) for 25-30 minutes, remove from the oven and allow to cool on a cake rack.
Cut the mango off the stone. Peel the flesh, cut into pieces and puree. Mix cream cheese, icing sugar and 1 tbsp. lemon juice with the whisk of the hand mixer until creamy. Pour into a piping bag with a large star-shaped spout, sprinkle a large tuff on each muffin. Decorate with mango puree.