Step 1: Preheat your oven to 350°F (175°C).
Step 2: In a large mixing bowl, combine melted coconut oil, granulated sugar, vanilla extract, and salt. Mix well and gradually add in all-purpose flour until crumbly.
Step 3: Press the crust mixture into the bottom of a greased 9x13-inch baking pan. Bake for 15-20 minutes until edges are lightly golden.
Step 4: In a separate bowl, whisk together granulated sugar, all-purpose flour, lemon zest, and salt for the filling.
Step 5: Add eggs and vanilla extract to the dry mixture, then pour in lemon juice. Whisk until smooth.
Step 6: Pour the lemon filling over the warm crust and spread evenly.
Step 7: Bake for an additional 20-25 minutes until the filling is set. Shake the pan gently; there should be minimal jiggle.
Step 8: Cool completely at room temperature and dust with confectioners' sugar before serving.