Chop your butter into small cubes and melt it at medium heat in a saucepan. The butter starts to sizzle when the water evaporates. After this the butter starts to brown, now you need to stir your butter so it does not burn.
You can brown your butter to light color with brown spots or a more nutty color with a deeper flavor. Lift your butter to cool down so it stops browning. Mix in the sugar and cool down to room temperature.
Add the liquid vanilla flavor to your butter. If you use vanilla sugar mix it and the baking powder in the flour. Add the flour to the cooled butter and mixit into a dough. If the dough feels too soft, place it in the fridge for 5-10 minutes.
Preheat your oven to 350F (175C). Shape the cookies with a spoon. Press the dough firmly to the spoon and slide it out with your fingers. You can place the cookies quite close to each other on the parchment paper, they hold their shape well in the oven.
Bake the cookies for 12 minutes if you made them with a soup spoon. If you used a smaller teaspoon bake them for about 8 minutes.
Let the cookies cool down before filling them with marmalade. Spread some marmalade on one cookie and add another as a lid on top. Press gently.
You can roll the cookie in sugar or sprinkle some powdered sugar on top.