For the cookie base:
4 oz. unsalted butter (110 gr. or 1/2 cup)
1/3 cup powdered sugar
1 egg yolk
1 tsp. vanilla extract
2 tbsp. milk
1 1/2 cups all-purpose flour
For the marshmallow filling:
2/3 cup white sugar
1/2 cup water
2 large egg whites
For the chocolate coating:
8 0z. semi-sweet chocolate
1/2 cup coconut oil
1. Preheat oven to 350F / 175C.
2. In a large bowl, mash the butter with the powdered sugar.
3. Add the egg yolk, vanilla extract, milk and flour. Mix until a dough forms. Use your hands to shape it into a block. Wrap in plastic and place in fridge for 20 mins.
4. Roll out the dough and cut out circles about 2 1/2 inches in diameter. Place on nonstick baking sheet and bake for 10-15 minutes until slightly golden. Re-roll out the unused dough into new circles. After baking let cool on wire rack.
5. For the marshmallow filling, add the sugar and water to a pot. Watch the temperature with a candy thermometer. On medium heat, stir often and be careful not to let the sugar burn. When it hits 220F/104C, beat the 2 egg whites in a large bowl until very fluffy. When the sugar water hits 243F/117C pour it slowly into the egg whites. Whip the mixture until it stiffens up and looks like marshmallow!
6. Pipe the marshmallow onto the cookies.
7. For the chocolate coating, melt the chocolate and add the coconut oil. Mix well. Pour over the krembos. It helps to use a spoon. If the marshmallow is very stuck onto the cookie, you can also dip it into the chocolate.
8. Carefully move the krembos onto a clean tray. Allow about an hour to cool or place in the fridge before serving. Note: if you refrigerate them, the crust won’t be shiny. However, these cookies are also delicious cold or frozen! An extra tip for the chocolate: everyone’s chocolate and coconut oil are different, so after you melt the chocolate, add the coconut oil one tablespoon at a time until is drips off a spoon smoothly and quickly.