In a bowl, combine all-purpose flour, granulated sugar, baking powder, and ground cardamom (if using).

In a separate bowl, whisk together milk and egg yolks.

Gradually add the wet ingredients to the dry ingredients, mixing until just combined.

In a third bowl, beat egg whites until stiff peaks form.

Gently fold the beaten egg whites into the batter, being careful not to deflate them.

Heat an Aebleskiver pan over medium-high heat and grease each divot with melted butter.

Once the pan is hot and the butter is sizzling, pour batter into each divot, filling them about 2/3 full.

Cook until the bottoms are golden brown and the batter is bubbly on top.

Use a wooden skewer to turn each Aebleskiver a quarter turn.

Continue cooking and turning until the Aebleskivers are golden brown all over.

Remove the cooked Aebleskivers from the pan with the skewer and place them on a plate in a warm oven to keep warm.

Repeat until all the batter is used.

Serve 3 Aebleskivers per serving with a light dusting of powdered sugar and warm syrup.

Optional: Before turning, add a teaspoon of jam or a small piece of apple to the center of each Aebleskiver.