Preheat your oven to 350°F and grease an 8-inch round cake pan or line it with parchment paper for easy removal.

In a large mixing bowl, whisk together the melted butter and granulated sugar until the mixture is smooth and slightly pale.

Add the eggs one at a time, whisking well after each addition, then stir in the vanilla extract until fully incorporated.

Sift in the all-purpose flour, ground cardamom, baking powder, and salt directly over the wet ingredients to avoid lumps.

Gently fold the dry ingredients into the wet mixture using a spatula until no streaks of flour remain, being careful not to overwork the batter.

Pour the batter into your prepared cake pan and smooth the top with the back of a spoon or an offset spatula.

If using pearl sugar or extra cardamom-sugar, sprinkle it evenly over the top of the batter before placing it in the oven.

Bake for 28 to 32 minutes, or until the top is golden brown and a skewer inserted into the middle comes out clean.

Remove the cake from the oven and let it cool in the pan for at least 15 minutes before transferring to a serving plate.