To make the biscuit, place the butter and sugar in a large bowl and beat together until light and fluffy. Add the eggs one at a time, beating well after each addition. Beat in the vanilla extract. 

Add in the flour and beat together until it forms a dough. 

Divide the dough into two pieces. Wrap in clingfilm and chill for one hour. 

Between two large pieces of parchment paper, roll out the first piece of dough to about 4mm thick. Remove the top piece of parchment and place an 11cm star cutter or template on top of the dough. Use a knife to cut around the star gently, without cutting through the paper underneath. Cut out four 11cm stars and place on sheets of non-stick parchment paper. You will need to re-roll the dough a few times. 

Repeat step four using cutters or templates measuring 10cm, 9cm, 8cm 6cm and 4cm, cutting out four stars in each size. Cut out one extra 4cm star for the top of the tree. 

Place the sheets of biscuits in the fridge and chill for at least 30 minutes, or place them in the freezer for 10 minutes. (These can be made the day before if you keep them chilled in the fridge). 

Preheat the oven to 180C / 160C Fan / Gas Mark 4. Gently lift the sheets of biscuits onto baking trays and bake for 12-15 minutes or until lightly golden. You will need to work in batches. 

Allow the biscuits to cool completely before decorating. 

For the buttercream, beat together the icing sugar, butter and vanilla extract until smooth.  

Squeeze the Dr. Oetker Extra Strong Green Food Colour Gel into the buttercream and beat until the colour is evenly mixed through. 

Spoon the buttercream into a piping bag with a small, round nozzle attached. 

To assemble the tree, place a teaspoon of buttercream onto your serving plate to hold the bottom biscuit in place. 

Using an 11cm star as the base, begin to stack your tree. Pipe ripples of buttercream onto each star and add a sprinkle of Dr. Oetker the Taste of Christmas Sprinkle Mix. Use gradually smaller stars as you move up the tree. 

Repeat this step with all the biscuits, placing each star at a slightly different angle to give a Christmas Tree Effect. 

Decorate the final 4cm star with Dr. Oetker Gold Decorating Icing and for some added sparkle spray with Dr. Oetker Gold Shimmer Spray. Place the gold star standing upright on the top of the tree. 

Add some extra Christmas Sprinkles if desired and enjoy!