How to do it…

1. In a large bowl, combine your dry ingredients by whisking together the flour, salt and baking powder.
2. Hopefully you have a fabulous KitchenAid mixer like I do, and if you do, in that (or if you don’t, use a hand mixer), beat the butter and sugar until smooth. Add the eggs one at a time, beating well after each addition. It’s a good idea between eggs and then before the next step to scrape down the sides of the bowl. Now, add the vanilla extract. Then it’s time to add the flour mixture (I do this in two or three goes, beating it in fully then adding more after more scraping - I don't know why I do this, it is probably totally unnecessary, but it makes me feel like somewhat of a cookie baker goddess, so I do it). Now beat this until you have a smooth dough.
3. At this point, cover the dough and pop it in the fridge until it is firm (about one to two hours, but if you're in a rush, you could get away with thirty minutes). As a side note: I would definitely give the dough fridge time for when you form the cookies, it will be easier/less sticky to work with and it will form nicer cookies and spread less when they bake. I suppose you could be lazy and not do this, though I have never been lazy whilst making Snickerdoodles (I don’t mess around with cookies, they have my avid attention and I give them all my energy), so I cannot say what will happen if you do.
4. Once the dough is chilled, preheat your oven to 400 degrees F (190 degrees C) and place rack in center of the oven. Don’t bother with greasing or lining your baking sheets, even rolled in cinnamon and sugar, these cookies don’t stick.
5. Make your coating in a shallow bowl that has room to move by mixing together the sugar and cinnamon.
6. Next up, shape the dough into 1 inch round balls (you can go way bigger, and I have, for larger cookies, but adjust the baking time).
7. Roll the balls of dough in the cinnamon sugar and place on your baking/cookie sheet giving them space to spread. But before popping these suckers in the oven, use the bottom of a glass to flatten each cookie just a wee bit.
8. Slide your sheets into the oven and bake for about 8-10 minutes (this will be shorter if you have a fan-assisted oven so keep an eye on them) or until they are light golden brown and firm around the edges. Don’t bake too long, you want the middle of the cookies to be soft. Slide the sheets out of the oven, give them a second to chill out, then scoop them off and put them on a wire rack to cool.