Preheat the oven to 350 degrees F. Line an 8x8 inch square pan.

In a medium pot, add the sugar and lime zest and rub together. Add lime juice, eggs, and flour and whisk until combined.

In a medium bowl, mix almond flour, coconut oil, maple syrup, vanilla extract, and salt until crumbly. Press into the pan and bake for 8-9 minutes.

While the crust cooks, whisk the lime filling over medium-low heat until thickened.

Strain the lime filling to remove lumps, then stir in butter and food coloring.

Pour over the warm crust and bake for 8-11 minutes until set.

Cool at room temperature for 1-2 hours, then chill in the fridge for at least 6 hours.

Dust with powdered sugar and cut into bars.

Store in an airtight container in the fridge for up to 4 days.