Preheat the oven to 180℃ / 350℉.
Combine all the dry ingredients in a large bowl. This is the brown rice flour, arrowroot, desiccated coconut, rapadura sugar, baking powder, and baking soda. Stir it all together to ensure it's well-combined then set aside.
Combine all the wet ingredients into another bowl. This is the lemon juice, lemon zest, yoghurt, eggs, vanilla extract, and macadamia oil. Whisk together until well combined.
Pour the wet mix into the dry mix and gently stir until the mix comes together. Set aside while you prepare your tray.
Line a muffin tin with paper baking cups. Fill each cup ⅓ of the way with muffin mix, dollop 1 Tablespoon of lemon curd on top, then top with more muffin mix. Spread the mix out evenly between the baking cups so you have 10 muffins of roughly the same size.
Bake for 20 - 25 minutes or until golden and a skewer inserted comes out clean.
Remove from the oven and leave them to sit in the tin for 5-10 minutes. Add another big dollop of lemon curd on top then serve. These are best served warm.