• Preheat the oven to 160°C/325°F/Gas Mark 3. Spray a six-hole muffin tin lightly with oil.
• Sift the plain flour with the baking powder into a large mixing bowl. Using a fork, stir in the wholemeal flour and mixed spice until thoroughly mixed.
• Pour in the oil and rub into the flour mixture with your fingertips.
• In a separate bowl, mix the egg, buttermilk and orange zest and juice together, then pour into the centre of the flour mixture and mix with a metal spoon, being careful not to over-mix - the batter should look a little uneven and lumpy.
• Spoon the batter into the prepared tin to come about three-quarters of the way up the sides of each hole. Bake in the oven for 30 minutes, or until golden brown and a skewer inserted into the centre of a muffin comes out clean.
• Remove from the oven and transfer to a wire rack. Brush with the marmalade and leave to cool.
• For the filling, mix the yoghurt with the marmalade and orange zest. Cut the warm muffins through the centre and fill with the yoghurt mixture and raspberries.

COOK'S TIP

• These muffins are best served warm, about 30 minutes after removing from the oven, and will work well with low-sugar raspberry jam instead of marmalade if you prefer.