Get Ready: Preheat your oven to 350°F (175°C). Lightly grease an 8-inch square baking dish.
Mix the Crust: In a large bowl, combine the almond flour, low-calorie sweetener, coconut flour, 1 teaspoon lime zest, and salt. Add the softened butter and mix with a fork until it’s all crumbly and well combined.
Press & Bake: Press this crust mixture firmly into the bottom of your prepared baking dish. Bake in the preheated oven for 10 to 15 minutes, or until it’s lightly golden. Take it out, but keep the oven on!
Prepare the Filling Base: In a medium saucepan over medium heat, whisk together the lime juice, coconut milk, powdered sweetener, melted butter, and 1 teaspoon lime zest. Stir until the sweetener fully dissolves, but be careful not to let it boil.
Thicken the Filling: Gradually whisk in the beaten eggs, stirring constantly for 5 to 10 minutes, until the mixture becomes foamy, airy, and begins to thicken. Remove from heat and pour this creamy filling evenly over your baked crust.
Bake the Bars: Return the dish to the oven and bake for another 10 to 15 minutes, until the filling is perfectly set in the center.
Toast the Topping: While the bars are baking, lightly toast the shredded coconut in a small skillet over medium heat for 2 to 3 minutes, until it turns a light golden brown. Remove from heat and toss with the remaining ½ tablespoon lime zest.
Chill Out: Once the bars are out of the oven, sprinkle the toasted coconut-lime topping over them. Let them cool at room temperature for 15 minutes, then transfer to the refrigerator to chill completely for about 2 hours.
Slice & Serve: Cut into 12 delicious bars and enjoy your refreshing, low-carb treat!