The night before, in a medium-sized mixing bowl, whisk sourdough starter, milk, sugar and cake flour until blended. Cover and set aside on counter overnight.

In the morning, stir in melted butter, salt, baking powder, vanilla and egg yolks.

Whip egg whites to just stiff peaks. Using a rubber spatula, fold egg whites into batter.

Brush the wells of an ebelskiver pan with butter and place over medium heat. When the bubbling of the butter subsides, spoon 1 tablespoon of batter into each well.

Spoon 1 teaspoon of diced strawberries into the center of each pancake. Top each with enough batter to fill the well. Cook the pancakes for 3 to 5 minutes or until bottoms are golden brown and crisp.

Use two wooden chopsticks or skewers to turn pancakes. Cook 2 to 3 minutes more or until lightly brown.

Repeat with remaining ingredients keeping cooked pancakes warm in a 200F oven.

To serve, arrange warm pancakes on individual serving plates and top with sliced strawberries, whipped cream, maple syrup and a dusting of powdered sugar, if desired.