Preheat the oven to 175 C (350 F). Line a large cookie sheet with parchment paper.
In a large bowl, cream together the butter, sugar and jaggery with a whisk or wooden spoon until smooth and creamy. If you’re doing it by hand, this would take around 3 minutes.
Add the egg, vanilla extract, salt and baking soda. Mix well.
Add the flour a little at a time and mix until fully incorporated.
Fold in the oats, dried cranberries and white chocolate chunks. At this point, the dough will be very thick and slightly sticky.
Refrigerate the dough for 30 minutes or place it in the freezer for 10 minutes*.
Grease your hands with a small amount of butter or oil. Roll 1.5 to 2 tablespoons of dough into a ball and place on the cookie sheet. Repeat for the rest of the dough, leaving about 2 inches space between each ball of dough*.
Use a spatula to flatten the cookies slightly until they are about 3/4 inch tall*. They will spread slightly as they bake.
Bake the cookies for 16 to 18 minutes*. The cookies are done when the tops are a light golden brown and the edges are slightly darker.
Leave on the cookie sheet for about 10 minutes, then transfer to a cooling rack to continue cooling. When they are fully cooled down, store in an airtight container. They will remain fresh up to 3 days.