Preheat your oven to 350°F (175°C).
Line the cake pan with parchment paper.
Grease the sides with butter.
This prevents sticking later.
Crack eggs into your mixing bowl.
Add sugar and beat until fluffy.
This takes about 3 minutes.
Pour in melted butter slowly.
Add lemon juice and vanilla extract.
Mix everything well together.
Add almond flour to the bowl.
Sprinkle in baking powder and salt.
Add the fresh lemon zest too.
Fold everything gently with your spatula.
Don't overmix the batter.
Pour batter into your prepared pan.
Smooth the top with your spatula.
Bake for 30-35 minutes until golden.
A toothpick should come out clean.
Let it cool completely before removing.