Time 1.5 hours

Serving 12 bars

For the Crust

• Unsalted butter, at room temperature, for greasing the pan
• 1½ cups/188 grams all-purpose flour
• 2 tablespoons/25 grams granulated sugar
• ½ teaspoon fine sea salt
• ¾ cup/170 grams unsalted butter

For the Filling

• 3 large eggs
• 1⅓ cups/267 grams granulated sugar
• ½ cup/113 grams unsalted butter, melted and cooled
• ½ cup/118 milliliters unsweetened coconut milk or whole milk
• 2 teaspoons apple cider vinegar or 1 tablespoon fresh lemon juice
• 1 teaspoon finely grated lemon zest (optional)
• 1 teaspoon vanilla extract
• ½ teaspoon fine sea salt
• 1 packed cup/100 grams shredded sweetened coconut
• ⅓ cup/54 grams bittersweet chocolate chips, preferably 72 percent to 80 percent cacao

Step 1
Prepare the crust: Heat oven to 350 degrees. Butter a 9-inch square pan and line with parchment, leaving some overhanging.

Step 2
In a food processor, pulse together flour, sugar and salt. Pulse in butter until crumbs form and the dough starts to come together. Press mixture into the prepared pan in an even layer. Bake until firm on top and lightly golden at the edges, 20 to 25 minutes. Transfer to a rack. You can bake the crust up to 6 hours ahead, or use it while it’s still hot.

Step 3
While the crust bakes, prepare the filling: Using the same food processor (no need to wash it out first), pulse together eggs, sugar, butter, coconut milk, vinegar or lemon juice, lemon zest (if using), vanilla and salt until well combined. Pulse in the coconut. Use a spatula to fold in the chocolate chips, if using.

Step 4
When the crust is baked, pour in the filling (crust can still be hot). Lower oven temperature to 325 degrees and bake until the filling is set when you jiggle it and the top is browned, 30 to 40 minutes.

Step 5
Transfer to a wire rack to cool completely, then chill for at least 2 hours. Cut into bars and serve.