• Line two large baking sheets with parchment paper. Preheat the oven to 350 F (180 C) for conventional oven, 330 F (165 C) for convection oven
• Position the oven rack in the middle of the oven. I recommend baking one sheet at a time. I get better result that way. Maybe it's my oven!

Prepare the cookie dough:

• Whisk all the dry ingredients in bowl and set aside
• In another mixing bowl, add softened butter and sugar. Use a sturdy wooden spatula to vigorously beat the butter and sugar until creamy and pale. You can also use an electric mixer to beat on high speed until they are pale and fluffy, about 2-3 minutes. If you use a standmixer, use a paddle attachment. Scrape the sides of the bowl with a rubber spatula halfway to make sure everything is creamed properly.
  
• Add the egg, lemon zest, osmanthus flower, and vanilla extract
  
• Continue to beat until combined. Scrape down the sides of the bowl with a rubber spatula if necessary. Don't overwork it
  
• Add the dry ingredients and use a spatula to fold the dry ingredients until you don't see any dry bits of flour. Again, don't overwork the dough.
  
• The dough should be soft and not sticky. It doesn't require any refrigeration and you can shape it right away

Shaping:

• Combine sugar with the crushed dried osmanthus flower in a bowl for coating
  
• Use a spoon to scoop the cookie dough, about 35-38 grams each, or use a large cookie scoop, size #40. The cookie dough will be about 1 1/2 inches in diameter. Roll it into a round dough ball. Pick up one dough ball and roll it into the sugar mixture.
  

If not baking on the same day:

• Place the shaped cookie dough on a baking sheet, not touching each other and flash freeze them in the freezer for about 30 minutes. Transfer to a freezer bag and they won't stick to each other. Push all the air out and seal the bag. They can be kept frozen for up to 2 months

If baking on the same day:

• Place it on the prepared baking pan, about 2 inches apart
  
• Place the baking sheet on the middle rack and bake for 9-10 minutes. They may seem undone when they first came out of the oven. Do not overbake
• Place the baking sheet on a cooling rack. You can use the back of a metal spoon to push the edge of the cookies to make them rounder and thicker. This has to be done as soon as the cookies are out of the oven before the edges are set.
  
• Continue baking the next batch

Cool down:

• Let the cookies cool on the baking sheet for 5 minutes and then transfer to a cooling rack to let them cool down. The surface will crinkle a bit as the cookies cool down. Enjoy warm or at room temperature
  

Storage:

• Let the cookies cool down completely before storing them. They can be kept at room temperature in an air-tight container for 2-3 days
• The baked cookies can be kept frozen. Simply transfer them to a freezer-friendly container. Keep them frozen no more than one month for the best result. Simply thaw at room temperature before serving