Preheat the oven to 180°C. Grease a 9-inch round cake pan and line it with parchment paper.
In a large bowl, mix 200 grams of all-purpose flour, 1 teaspoon of baking powder, and a pinch of salt. Set aside.
In another bowl, beat 200 grams of softened unsalted butter and 200 grams of powdered sugar until light and fluffy.
Add 4 eggs, one at a time, to the butter-sugar mixture, beating well after each addition.
Gradually fold in the flour mixture into the wet ingredients, mixing gently until just combined.
Stir in 1 teaspoon of vanilla essence and 150 grams of chopped walnuts.
Pour the batter into the prepared cake pan and smooth the top.
Bake for 35-40 minutes or until a toothpick inserted in the center comes out clean.
Allow the cake to cool in the pan for 10 minutes, then transfer it to a wire rack to cool completely.