Preheat oven at 170°C/340°F.

In a large bowl, add the room temp (or softened) butter. Add sugar and salt. Mix them using a spatula so that the sugar the fly out. Then switch to an electric mixer. Mix on high speed for at least 1-2 minutes or until creamy, pale and fluffy.

Add the heavy cream and vanilla extract. Mix till combined.

Sift the cake flour and cornstarch in 2 batches. Fold in using a spatula. Sift the remaining dry ingredients until the flour disappear. Pay attention on the consistency of the dough. It will be soft and smooth and a little sticky and wet too.

Divide the dough into 3 bowl. I do recommend using a weighing scale because the consistency is very important for piping or spritz dough.

For the second and third bowl, add in the green tea and cocoa powder respectively. You may also add green and brown food colouring into respective dough colour to make them more vibrant. This is definitely optional.

Transfer the doughs into a piping bag respectively. Double up the piping bag if yours is thin like mine. A thin piping bag will cause breaking of the bag. Also it will ease your piping.

Bake in preheated oven at 170°C/340°F for about 15-17 min. For 15min, the cookies might be softer than 17min bake, so it really depending on how crispy you desire your cookies to be.

Let it cool completely.

Melt some milk chocolate and white chocolate for the side deco. Dip one side of the cookies and sprinkle with some colourful sprinkles.

Cookies are ready to serve.