In a large bowl (or mixer with paddle attachment or food processor), whisk together the flour, sugar and baking powder, create a well in the middle and add the slightly beaten egg and yolk and butter. Mix together until almost combined then move to a slightly floured flat surface and gently knead the mixture to form a soft dough ball. Wrap the dough in plastic wrap and refrigerate for 30 minutes.
Remove the dough from the fridge, divide it in half (roll out a half at a time, the remainder keep chilled), roll out on a lightly floured flat surface to approximately 1/4 inch thickness or less if you prefer. Cut out with your favourite cookie cutters, place the cookies on a parchment paper lined cookie sheet, chill the cookies again while the oven is pre-heating.
Pre-heat oven to 350F (180C).
Bake until lightly golden, approximately 10-12 minutes, let cool 5 minutes on cookie sheet, then move to a wire rack to cool completely. Dust with powdered sugar, they can also be made into sandwich cookies, top one side of the cookie with your favourite filling, such as hazelnut cream or even jam. Enjoy!