In a large mixing bowl, measure and take butter at room temperature (softened or slightly melted). Add the powdered sugar. Cream together using an electric mixer (low speed) or a hand mixer. Mix the softened butter and sugar thoroughly, until the butter mixture has a fine paste consistency.
Sift and add the flour. Mix half a teaspoon of baking soda into the flour. If using self-rising flour, don’t use baking soda — replace it with 1/4 tsp of plain salt.
Mix again (cut and fold method) using a spatula. The dough will turn into a wet crumbly texture. Do not overmix.
Add a teaspoon of vanilla extract and mix well. You can also use almond extract if you prefer that flavor.
Start kneading again to form a smooth ball. If your dough is still powdery and unable to knead together, you can add a few tablespoons of oil, water, or milk.
Now shape the dough lengthwise and roll the dough in parchment paper or plastic wrap tightly. You roll it rounded or squared to either make round or square-shaped butter cookies.
Place the tightly wrapped dough inside a refrigerator for 30 mins or freezer for 15 mins to harden a bit.
Preheat the oven to 350 F (180 C).
Grease or line a baking sheet or cookie sheet.
After 30 mins, take out the dough from the freezer, remove the wrap and cut into slices that are slightly under 1/2 inch (or about 1 cm) thick, using a sharp knife. Place the cookie dough slices on the prepared baking sheet, giving enough space.
Bake for 15 mins in a convection oven or 20 mins in a regular oven.
Once done, let them cool down for half an hour. (Will become crispy after cooling.)