Pre heat oven to 180°C fan-forced and line 2 large baking trays with baking paper

Add melted butter and sugars into a large mixing bowl and whisk to combine. Add the egg and vanilla and mix until smooth.

In a separate bowl whisk together flour, baking powder, bicarbonate of soda and salt. Add the dry ingredients to the butter mixture and mix until a soft dough starts to form. Add in milk chocolate chips and continue mixing until all ingredients are just combined, being careful not to overmix.

Use a tablespoon to portion out the dough and shape into balls. Place onto the prepared baking trays leaving 5cm of space between each ball. Bake for 12 minutes. Halfway through baking open the oven door, lift each baking tray up a few centre meters and tap against the oven rack. Close the oven door and continue to bake - See tip.

Remove from oven and leave to cool for 5 minutes on the trays before transferring to a cooling rack to cool completely. Spoon melted white chocolate into a piping bag, pipe a cross onto each cookie. Leave for 5 minutes for chocolate to set before enjoying.