To form the dough:

Cup of Yum
1. Cut parchment paper into 3 1/2 x 3 1/2 inch (9x9 centimeter) squares and brush the top of each with oil.
2. In a large saucepan, combine the water, butter, vanilla sugar, and salt over high heat.
3. Once the butter has melted and the mixture comes to a boil with the sugar and salt dissolved, remove from heat.
4. Use a wooden spoon to immediately stir in the flour.
5. Place the pan back on the stove over medium low heat. Continue to stir until a dough forms and pulls away from the bottom and sides of the pan, about 1 minute.
6. Transfer the dough to the bowl of a stand mixer or a large bowl and allow to cool until no longer hot, but still warm to touch.
7. Using a stand or hand mixer, beat the eggs, one at a time, followed by the baking powder into the cooled dough at high speed to form a smooth and glossy mixture.

To assemble:

1. Fill a deep saucepan with 2-3 inches (5-8 centimeters) of oil and place over medium heat.
2. Attach a large star tip to large piping bag. Fill the bag with dough (in batches if needed).
3. Pipe rings of dough onto the greased parchment paper.
4. Once the oil is 350˚F (180˚C), place the piped dough, being careful not to overcrowd, into the pan paper side up. Gently remove the paper and fry the doughnuts on each side until golden.
5. Use a slotted spoon to transfer to a towel lined plate. Repeat with remaining batter.
6. Place a wire rack over a sheet of parchment.
7. In a large bowl , whisk lemon juice, rum, or water into the powdered sugar until a thin and smooth glaze comes together. If too thick, add more liquid. If too thin, whisk in more sugar.
8. Dip each warm Spritzkuchen into the glaze and place on wire rack to set. They are best served the day they are made.