Combine the flour, haldi doodh masala, cream of tartar, ½ teaspoon cinnamon, salt, and baking soda in a medium bowl, mix well, and set aside.

Place the butter, white granulated sugar, and brown sugar in a large bowl. Using an electric hand mixer, beat the butter and sugar on medium-high speed until it is light and fluffy, scraping the bowl as needed, about 3 to 4 minutes. Alternatively, you can use a stand mixer with a paddle attachment.

Add the eggs and vanilla extract and beat until they are fully incorporated, about another 1 to 2 minutes. Add the dry ingredients to the butter mixture and gently incorporate the dry ingredients with the mixer on low until a homogenous dough forms, about 30 seconds to 1 minute. If there are any spots of flour, use a spatula to fold it in. (You want to be careful not to overmix the flour because it will result in tough cookies.) Wrap the dough in plastic wrap and refrigerate for 2 hours to overnight.

When you are ready to bake the cookies, preheat the oven to 375°F. Line a couple sheet pans with parchment paper or baking mats and set aside.

In a shallow bowl mix together the demerara sugar and the remaining 1 tablespoon cinnamon.

Remove the dough from the refrigerator. Taking a 2 tablespoon-sized piece (25g) of cookie dough at a time, roll the dough between your palms to form a ball. Then, gently roll the dough ball in the cinnamon sugar mixture, pressing it in the mixture so the sugar adheres to the outside. Place the sugared dough ball on the parchment-lined baking sheet, spacing the cookies about 2 inches apart. Repeat with the dough until both trays are full and then return any leftover dough to the refrigerator.

Bake the cookies for 6 minutes. Then, taking one tray at a time, bang the tray on the counter several times and return them back to the oven, placing the tray that was on the top shelf on the bottom and vice versa. Bake until the edges start to crisp, about another 4 minutes. Remove from the oven, allow to cool on the pan for 5 minutes, and then transfer to a wire baking rack to cool. Repeat the rolling, sugaring, and baking process with the remaining dough. When cool, enjoy or store in an airtight container for up to 1 week.