Preheat the oven to 180ºc fan and prep 12 tulip cases
Add the flour, sugar and butter together and rub to breadcrumbs and leave to the side for now
Add the butter, oil, sugar and eggs to a bowl and mix
Add the vanilla and lemon zest mix
Add the flour, baking powder and salt and mix
Add the buttermilk and stir together
Add the white chocolate chips and stir
Split between 12 tulip cases evenly
Pipe the lemon curd into the muffins in the cases - I insert a piping bag with the end snipped off into the top of the muffin and pipe the lemon curd in
Sprinkle over the streusel topping
Bake for 22-25 minutes until golden
Leave to cool for 20-30 minutes and enjoy
Notes
The muffins are delicious warm, but the lemon curd will be quite runny fresh out of the oven. Leave them to cool to room temp and it’ll thicken again
The muffins are best in the first couple of days, but do last up to four days at room temp