Cream the butter and sugar. In a large mixing bowl, beat the softened butter and caster sugar together until the mixture turns pale and fluffy — you'll notice the colour shift from yellow to a soft cream, and the texture will feel light and airy when you lift the beaters. This should take about 3 minutes with an electric mixer.

Add the wet ingredients. Crack in the egg and pour in the vanilla extract. Beat again until everything is fully combined. The batter will look slightly glossy and smell wonderfully sweet at this stage.

Mix the dry ingredients. Sift the flour, baking powder, and salt into the wet mixture. Stir with a wooden spoon or spatula until a soft dough forms. You'll know it's ready when the dough pulls away from the sides of the bowl and no dry patches remain — it should feel smooth and slightly tacky to the touch.

Add the colour. Drop in a few drops of green gel food colouring and mix thoroughly. Keep adding until you reach a rich forest green shade. The colour will deepen slightly as the dough rests, so aim for a shade just lighter than you want the final cookie to be.

Shape the trees. Preheat your oven to 180°C (fan). Line two baking trays with parchment paper. Take a tablespoon-sized piece of dough and roll it into a ball, then pinch the top to form a point and flatten the bottom slightly — you're aiming for a rough triangle shape about 1cm thick. Place each tree on the tray, leaving 3cm between them for spreading. I make this at least once a week — it's become a family favourite, and the kids love the shaping part.

Bake until set. Bake for 10-12 minutes. The cookies are ready when the edges are just beginning to turn golden brown — you'll catch a faint nutty smell from the butter, and the tops will look dry rather than shiny. Don't wait for the centres to darken; they'll continue cooking from the residual heat on the tray.

Cool and decorate. Let the cookies sit on the tray for 5 minutes — they'll be soft when first out of the oven but will firm up beautifully. Transfer to a wire cooling rack. Once completely cool, melt the white chocolate chips in the microwave in 20-second bursts, stirring between each. Dip the top of each tree cookie into the melted chocolate to form a star, then immediately sprinkle with decorations before the chocolate sets.