In a bowl take butter and powdered sugar and beat until combined.
Then add eggs, vanilla essence, and salt and beat until well combined.
Now add the flour until dough is moist and holds together, but doesn’t stick to your hands,you can add more dough if needed.
Now take out the dough, from bowl and cut in two equal parts.
Now cut the other half in 6 pieces but the outer layers of the rainbow will need a little bit more dough, so make two of them slightly larger than the others.
Now add diffrent food colour in each piece of dough and knead until the colour mix properly in the dough.
Now, starting with purple, roll the dough into a log, this will be the center of the rainbow.
Than roll the blue dough slightly longer and wider than the purple and wrap the log of purple dough.
Repeat the process with green, yellow,orange and red doughs.
Now wrap the log of dough in plastic wrap and refrigerate for 30 minutes.
After 30 minutes take out dough,remove the plastic wrap and cut dough in half parts to make rainbow shape.
Now divide the remaining plain dough in two parts and roll slightly longer and wider than the rainbow log, place the rainbow log in the centre and wrap the plain dough around it.
You can pinch together any cracks.
Repeat with the other halves and wrap dough log with plastic wrap and refrigerate for 30 minutes.
Once chilled, remove the plastic wrap and cut cookies about 1/4-inch.
Now pre-heat the oven to 180˚C.
Place cookies on baking tray and bake it for 20 minutes.
Cool on a cooling rack.
Than transfer to serving tray and serve with hot tea..