Cream the sugar and margarine together in the bowl of an electric mixer on low to medium speed. (Use the paddle attachment). Mix until thoroughly incorporated - for about one minute. Scrape down the sides of the bowl with a plastic spatula and mix again for a few seconds more.
Add eggs slowly and mix. Scrape down the bowl with your spatula at least once and mix again.
Add vanilla extract. Stir briefly.
Sift your dry ingredients together. (Flour, cinammon and salt).
Add all of the flour mixture to the bowl. (Loosely cover your mixer with a large tea towel). Mix on low speed for 3o seconds. When the dough clumps around the paddle attachment it's ready.
Roll the dough out between 2 large pieces of parchment paper. Place on a baking sheet and into the fridge for a minimum of 1 hour.
Roll out the dough further if you need to, and cut out cookie shapes. Place on parchment paper-lined baking sheet. Re-roll scraps and repeat. The best batch of dough to work with is the first one. Once the dough gets re-rolled a few times it becomes harder to work with, and the cookies won't hold their shape as well when baked. If the dough gets too soft, put it in the freezer for a few minutes and try again.
Once all cut out, put cookie dough shapes back into the fridge for 10 minutes to 1 hour to chill again. They will then hold their shape better when baked.
Preheat your oven to 350°F or 176°C.
Bake cookies for 8-12 minutes or until the edges become golden brown. The baking time will depend on the size of your cookie.
Let cookies cool to room temperature and serve as is or decorate!