Preheat oven to 350°F (160°C fan). Line 2 baking sheets with parchment paper.

Beat softened butter and superfine sugar in a large bowl until creamy (about 1 minute on medium speed).

Add the large egg and vanilla extract, then beat until fully combined and smooth.

In a separate bowl, whisk together the all-purpose flour, baking powder, and salt.

Gradually add the dry ingredients to the wet ingredients. Start mixing slowly, then beat until the flour is incorporated and the dough is clumpy. Do not overmix.

Dust your work surface with flour, scrape the dough out of the bowl, and pat it together. Divide the dough in half and shape each half into a disc.

Roll out one dough disc to 1/8 inch (for thinner, crispier cookies) or 1/4 inch (for thicker, softer cookies). Sprinkle flour under and over the dough to prevent sticking.

Use cookie cutters to press out desired shapes and carefully transfer them to the prepared baking sheets using a knife or spatula. Bake for 8-12 minutes, or until edges are lightly golden. Let cool completely before icing. Refrigerate any unbaked dough for up to 3 days.