Preheat the oven to 180C/350F and line a 12 hole muffin tin with liners.
Place the sugar, eggs and lime zest into a large bowl and whisk until smooth and there are no lumps.
Gradually add in the melted butter, whisking while you do this, until everything is smooth and well combined.
Add in the flour, bicarbonate of soda, baking powder and salt and whisk until the mixture starts to come together, then add the yoghurt and continue to whisk until there are no lumps of flour and you have a smooth, well combined batter.
Divide the batter between the muffin liners; fill them 3/4 of the way. I used a heaping 2tbsp cookie scoop.
Place in the oven for 12-15 minutes, until risen, golden and an inserted skewer into the centre comes out clean.
Leave to cool in the pan for 10 minutes before transferring to a wire rack, with kitchen paper beneath it, to cool completely.
Once cool, make the glaze: Sift the icing sugar into a medium sized bowl and add the lime juice 1tbsp at a time, whisking until you have a thick glaze which ribbons when you pull the whisk out. You want a fairly thick consistency that will stay on the top of the muffin and just a bit of it drizzles down the side.
Garnish with fresh lime zest if desired.
Lime and Yoghurt Muffins will keep in an airtight container, at room temperature, for 4 days, or in the fridge for 6 days without the glaze. If glazed, they'll keep for 3 days and the glaze will sink into the muffins. I would keep the muffins unglazed for breakfast on the go and if you're serving them glaze just before serving.