Preheat the oven to 350°F. Line an 8x8-inch square pan (avoid using a 9x9-inch pan, as it will be too large). Tip: Sticking with an 8x8-inch pan ensures the right thickness and bake time.

In a medium pot, combine the sugar and lime zest, rubbing them together with clean fingers for about 30 seconds to release the lime’s flavor into the sugar.

Then, add the lime juice, eggs, and flour, whisking until the mixture is smooth and fully blended with no visible egg streaks. Leave the butter and any food dye out for now, and set the pot aside.

In a medium bowl, combine the almond flour, coconut oil, maple syrup, vanilla extract, and salt. Use a fork to mix everything until it forms a thick, crumbly texture.

Transfer the mixture to your pan, pressing it down evenly with your fingers. Bake for 8-9 minutes, or until the edges are lightly golden.

Remove from the oven and let the crust cool for 5 minutes, leaving the oven on.

While the crust is baking, set the pot over medium-low heat and whisk continuously until the mixture thickens enough to coat the back of a spoon, about 6 to 8 minutes.

Once thickened, remove from the heat.

Set a fine-mesh sieve over a medium bowl, then pour the mixture into the sieve. Use a spoon to press and work the filling through, straining out any solids.

Into the bowl with the warm lime filling, stir in the butter until it melts completely. If desired, add a few drops of green food dye for a bright green hue.

Pour the filling over the warm crust, tilting the pan or using a spatula to spread it evenly.

Return the pan to the oven and bake for an additional 10 minutes, until the filling is set and only slightly jiggles when the pan is gently shaken.

Let the bars cool at room temperature for 1 to 2 hours, then place them in the fridge to chill for at least 6 hours, or up to 2 days.

Dust with powdered sugar, then use a clean, sharp knife dipped in water to cut into 16 bars.

Remember to clean and wet the knife after each cut—it may be a bit tedious, but it ensures a clean, perfect slice every time!

For an extra pop of flavor, sprinkle a bit more lime zest on top if you’d like a touch of added zing.

For storage, place any leftover bars in an airtight container and refrigerate for up to 4 days.

If stacking, separate layers with parchment paper to prevent sticking.

You may want to dust the bars with a fresh layer of powdered sugar before serving, as it tends to dissolve while chilled.