In a small saucepan, combine egg yolks, lemon juice, and sugar. Stir constantly over low heat until the mixture thickens and coats the back of a spoon.

Remove from heat and add the butter. Stir until fully melted and smooth.

Strain the lemon curd into a bowl, cover with plastic wrap (touching the surface), and let cool for 30 minutes. Refrigerate until ready to use.

Preheat oven to 180°C (350°F). Line an 8x8-inch pan with parchment paper.

In a large bowl, whisk eggs vigorously until foamy. Add granulated sugar and whisk for 1–2 minutes.

Stir in oil, lemon juice, lemon zest, vanilla, and yogurt until combined.

In a separate bowl, mix together flour, baking powder, and salt.

Alternate adding dry ingredients and milk to the wet mixture, beginning and ending with the dry (flour, milk, flour, milk, flour).

Batter will be thin but don’t worry! Pour into prepared pan.

Bake for 25–30 minutes or until a toothpick inserted in the center comes out clean.

Let the cake cool in the pan for 10 minutes, then transfer to a wire rack.

While cooling, you can make the lemon syrup by heating sugar and lemon juice until dissolved. Brush or drizzle over the cake once cooled (optional).

In a bowl, cream butter and cream cheese until smooth. Add icing sugar and beat until light and fluffy.

Add spoonfuls of lemon curd and gently swirl over the frosting.

Slice and serve!