Creating your delightful Lemon Clair Cake is an enjoyable journey. Follow these steps to ensure incredible results:

1. Preheat Oven: Start by preheating your oven to 350°F (175°C). Grease and flour two 9-inch round cake pans.

2. Mix Dry Ingredients: In a large bowl, whisk together the flour, baking powder, and salt until well combined.

3. Cream Butter and Sugar: In another bowl, beat the softened butter and granulated sugar together until light and fluffy.

4. Add Eggs: Mix in the eggs one at a time, ensuring each is fully incorporated before adding the next.

5. Combine Wet Ingredients: Stir in the milk, lemon zest, lemon juice, and vanilla extract into the butter mixture.

6. Mix Dry and Wet Ingredients: Gradually add the dry ingredients into the wet mixture, mixing until smooth and well combined.

7. Pour Batter: Divide the batter evenly between the two prepared cake pans.

8. Bake: Place the pans in the preheated oven and bake for 35-40 minutes. The cakes are done when a toothpick inserted in the center comes out clean.

9. Cool the Cakes: Once baked, remove the pans from the oven. Allow them to cool in the pans for about 10 minutes, then transfer the cakes to wire racks to cool completely.

10. Prepare Whipped Cream: In a mixing bowl, combine the heavy cream and powdered sugar. Whip until soft peaks form.

11. Assemble the Cake: Once cool, place one cake layer on your serving plate. Spread a layer of whipped cream on top, then place the second layer over it. Top the second layer with more whipped cream.

12. Garnish: Optionally, garnish with additional lemon slices for a beautifying touch.

By carefully following these instructions, you will create a stunning and delicious Lemon Clair Cake that is sure to impress.