1. Preheat your oven to 350°F (175°C) and grease an 8×8-inch baking dish.
2. In a large mixing bowl, combine the flour, sugar, salt, and baking powder. Stir until well mixed.
3. Add the melted butter, eggs, lemon juice, lemon zest, and vanilla extract to the dry ingredients. Mix until just combined, being careful not to overmix.
4. Pour the batter into the prepared baking dish, smoothing the top with a spatula.
5. Bake for 25-30 minutes, or until the edges are golden and a toothpick inserted into the center comes out clean.
6. Let the dessert cool in the baking dish for at least 10 minutes before slicing. Dust with powdered sugar before serving, if desired.

As someone who learned to cook by watching my abuela, I believe in trusting your senses. While baking, you’ll know it’s ready when you smell that irresistible lemon aroma wafting through your kitchen.