Cream the butter and sugars

• Beat the softened butter with the granulated sugar and powdered sugar until pale and fluffy.
• Scrape down the sides of the bowl.

Add the wet ingredients

• Beat in the egg and the vanilla extract until fully combined.

Make the green dough

• Whisk the flour, baking powder and salt together.
• Add the dry mix to the butter mixture and mix just until a dough forms.
• Add the green food coloring and knead until the color is even.

Chill the dough

• Flatten the dough into a disc, wrap it and refrigerate until firm.

Shape the eggs

• Roll the dough out to about 5 mm thick.
• Cut out egg shapes with an egg-shaped cutter and place them on a lined baking tray.

Bake

• Bake at 175 °C until the edges are just set and barely golden.
• Let the cookies cool completely on the tray.

Decorate

• Pipe white icing spots onto the cooled green cookies to look like Yoshi's eggs.
• Let the icing set before serving.