Photograph: Maja Smend
Heat the oven to 200°C, fan 180°C, gas 6. Put 12 paper cases in a muffin tray or line the muffin moulds with scrunched squares of baking paper.
Cream the butter and sugar together in a large bowl until light and fluffy. Beat in the eggs, one at a time. Sieve the flour, baking powder and a pinch of salt into the bowl and fold in lightly until only just combined; do not overwork. Fold in the passionfruit until just combined.
Divide half the mixture between the paper cases, then distribute half the raspberries among them. Top with the remaining muffin mix; stud the tops with the remaining raspberries.
Bake for 15-20 minutes until the muffins are golden and spring back when gently pressed.
Kitchen secret: the trick to a good muffin is not to overmix when you add the flour – better to undermix for a light, crumbly texture.