How to make
In a bowl sift the flour with a pinch of salt, two teaspoons of baking powder and a pinch of vanilla.
Add two eggs and one yolk. Pour the oil and mastic. Add the chopped butter. Knead a soft butter dough.
Wrap the dough in a piece of cling film and store it in the refrigerator for 30 minutes.
On a floured surface, roll out the chilled dough into a rectangle.
Pour the jam in the middle lengthwise.
Fold one end over the jam and the other one on top. Pinch both ends closed. Transfer the roll into a baking tray lined with baking paper.
Spread it with a beaten egg white and sprinkle it with crystal sugar. Bake the butter roll at 360°F (180°C) in a preheated oven with a fan for about 35-40 minutes.
Cool it on a wire rack and then slice it.
Enjoy!
