Place all the ingredients in a bowl and briefly mix until smooth.
Transfer the mixture to a piping bag fitted with a round tip with a ⅜-inch (1 cm) opening. Pipe rounds about 1¼ inches (3 cm) in diameter onto a baking sheet lined with parchment paper.
Bake the bitterkoekjes at 375°F /190°C (conventional oven) for 13-16 minutes, until golden brown.
How to store
Store in an airtight container at room temperature for up to one week.