Cooking oil spray, to grease
125g unsalted butter, melted
1 cup brown sugar
1 free-range egg
11⁄2 cups plain our
1 tsp baking powder
100g mixed sprinkles
1⁄2 tsp bicarbonate of soda
300g chocolate bits (use white, milk or dark, or combo of all 3)
50g milk or dark chocolate melts, melted
Preheat oven to 160°C fan-forced (180°C conventional). Grease a 23cm round fluted silicone pan with cooking oil. Put pan on an oven tray large enough to sit level.
Put melted butter and sugar in a large bowl and mix with a wooden spoon until combined.
Add egg and mix again.
Stir in flour, baking powder and bicarb until combined and a soft, smooth dough forms.
Stir in 1⁄2 cup mixed sprinkles.
Tip: You can actually add any sprinkles you prefer, like little hearts of polka dots, too for added cuteness!
Press dough into pan and smooth surface then bake for 35 minutes or until firm to touch. Remove from oven and set aside for 20 minutes to cool slightly. Turn out cookie onto a wire rack, decorative side up. (You can even serve it warm at this stage without decoration).
To make icing:
Put 1 free-range egg white in the bowl of an electric mixer and beat on low, using whisk attachment, for 2 minutes or until frothy.
Leaving motor running, gradually add 11⁄4 cups pure icing sugar, 1⁄4 cup at time. Beat well between each addition.
Add 1⁄4 tsp cream of tartar and 1 tsp lemon juice.
Continue whisking until thick. Spoon icing into a disposable piping bag and snip tip to form a 2mm-wide opening.
Pipe words or decorations onto cookie to decorate. Scatter entire cookie with extra sprinkles and set aside for 30 minutes or until icing sets firmly. Cut into wedges. Serve.