Preheat your oven to 350°F (175°C). Grease and line a 9×13-inch (or 23×33 cm) cake pan with parchment paper.
In a bowl, whisk together flour, baking powder, and salt. Set aside.
In a large bowl, cream the softened butter and sugar together until light and fluffy (about 3 minutes).
Beat in eggs one at a time, mixing well after each. Stir in vanilla extract.
Add the dry ingredients in 3 parts, alternating with milk, beginning and ending with flour. Mix until just combined.
Pour batter into the prepared pan and bake for 25–30 minutes, or until a toothpick inserted in the center comes out clean. Let cool completely.
2️⃣ Prepare the Yema Filling
In a heavy-bottomed saucepan over medium-low heat, whisk together the sweetened condensed milk and egg yolks until smooth.
Cook for 12–18 minutes, stirring constantly with a wooden spoon or silicone spatula, until thick and pudding-like. Do not leave it unattended—it can burn easily.
Remove from heat and stir in the butter and vanilla until glossy. Cool until spreadable.
