Preheat your oven to 350°F (175°C). Gather your tools: a mixing bowl, a whisk, and a greased 9-inch cake pan.

Cream ½ cup of softened unsalted butter with 1 cup of granulated sugar until light and fluffy, about 3-4 minutes.

Add 3 large eggs one at a time, mixing well after each addition.

Stir in 2 tablespoons of fresh lemon juice, 1 tablespoon of lemon zest, and ¾ cup of milk, blending until combined.

In a separate bowl, sift together 1 ½ cups of all-purpose flour, 1 teaspoon of baking powder, and ¼ teaspoon of salt.

Fold the dry ingredients into the wet mixture until just blended.

Pour the batter into the greased cake pan, smoothing the top.

Spoon the lemon custard layer over the cake batter.

Bake for 35-40 minutes, until a toothpick inserted comes out clean.

Cool in the pan for about 10 minutes before transferring to a wire rack.