Well done! You found the secret

So here is step by step instructions on how to bake a cake

• Prep the Oven: Preheat your oven to 175 degrees celsius (350 degrees fairenhiet). Grease and flour a 9-inch square cake pan.
• Cream Butter and Sugar: In a mixing bowl, beat the softened butter and sugar together with an electric mixer until the mixture is light and fluffy (about 3–4 minutes).
• Add Wet Ingredients: Beat in the eggs one at a time, then stir in the vanilla extract.
• Combine Dry Ingredients: In a separate bowl, whisk together the flour, baking powder, and salt.
• Mix Together: Gradually add the flour mixture to the butter mixture, alternating with the milk. Start and end with the flour, mixing just until combined to avoid overworking the batter.
• Bake: Spread the batter into the prepared pan. Bake for about 30 minutes, or until a toothpick inserted into the centre comes out clean.
• Cool: Let the cake cool in the pan for 10 minutes before turning it out onto a wire rack to cool completely before frosting.