Preheat oven to 190C/375F and grease a 12 hole muffin tin.
Place the flour, sugar and lemon zest into a large bowl and stir until just combined.
Place the lemon juice, yoghurt, vegetable oil, eggs and vanilla extract into a jug and beat lightly.
Pour wet into dry and mix by hand until just combined and there are no lumps of flour - don't be tempted to overmix your batter otherwise you'll have rubbery muffins!
Fill each muffin hole half way and then place 1/2tbsp of lemon curd into each muffin hole, pressing it into the batter ever so slightly.
Top each muffin with the remaining batter, each hole should be filled level.
Place in the oven for 15-20 minutes until risen, golden around the edges and an inserted skewer into the centre comes out clean.
Leave to cool in the pan for at least 10 minutes, before transferring to a wire rack to cool completely.
Once cooled, muffins will keep in an airtight container, at room temperature for 4 days.