In the bowl of a stand mixer fitted with the paddle attachment, beat the butter, vanilla extract, and sugar on medium until light and fluffy, about 3 minutes. Scrape down the sides. Add the egg, beat until combined, and scrape down the sides.
Add the flour & baking powder to the mixing bowl and beat on low for 2-3 minutes, until crumbly in the middle but sticking to the sides of the bowl.
Turn the dough out onto a large piece of parchment paper and use your hands to bring together into a kind of rectangle shape. Place another large sheet of parchment paper on top of the dough and use a rolling pin to roll the dough out to a thickness of 1/8-1/4 inch between the two sheets. Transfer the dough to the fridge and leave to chill for at least 1-hour.
Preheat the oven to 180°C. Using a gingerbread man cookie cutter, stamp out the dough. If the dough starts to get warm or malleable at any stage, return it to the fridge for 5-10 minutes. When stamped, transfer the cookies to a parchment lined tray - spacing them about 1-inch apart - and pop in the freezer for at least 10-minutes.
Bake the cookies in the preheated over for 9-10 minutes, or until the edges of the cookies are just beginning to go golden brown. Leave the cookies to cool on the baking tray for at least 15-minutes before moving to a wire rack to cool completely.