Place the flour and baking soda in a bowl. Whisk until they are fully combined. Place the butter, sugar, egg, and vanilla in a bowl and beat until the ingredients are incorporated and the mixture is light and fluffy. Pour the flour mixture into the bowl of wet ingredients. Use a long-handled spoon to stir the batter until you can no longer see the specks of white flour. Use a spoon or a small ice cream scoop to place even amounts of cookie dough onto the baking sheet. Space them an inch or two apart to allow the cookies room to spread. Use the bottom of a drinking glass to press the cookies flat. This will give the cookies a sweet, crunchy finish. Place the baking sheet in the oven and bake the cookies for 15 minutes, or until the tops turn slightly golden. Remove them from the oven and place them on a cooling rack or a plate. Let them cool for a minute or two before eating. Sugar cookies are fun to decorate with glaze or icing. Add sprinkles or edible glitter to make them look festive.

TL;DR in Vietnamese:
Làm nóng trước lò nướng đến 180 độ C. Trộn các nguyên liệu khô. Đánh bông các nguyên liệu ướt trong một bát riêng. Trộn hai loại nguyên liệu khô và ướt với nhau. Múc bột đặt lên khay nướng. Ép phẳng bánh. Rắc đường lên bánh. Nướng bánh. Để bánh nguội. Trang trí bánh.