(Adapted from Bouchon. Read about it in Cookies and Chocolate Mousse.)
Makes approximately 32 cookies.
8 tablespoons unsalted butter, softened
1/4 cup plus 1 teaspoon confectioners’ sugar
1 vanilla bean, split
About 1 cup all-purpose flour
1/4 cup granulated sugar
1 teaspoon ground cinnamon
Combine the confectioners’ sugar and butter and beat until blended. Scrape the seeds from the vanilla bean with a paring knife, add the seeds to the bowl, and mix until well combined. Add about 3/4 cup flour and mix until combined. Continue to add flour until the dough comes together in a smooth mass and no longer sticks to the sides of the bowl. Wrap the dough in plastic wrap and refrigerate for about an hour to an hour and a half to firm up slightly.
Dust a flat surface with flour. Halve the dough and roll each piece into a log about 6 1/2 to 7 inches long and about 1 inch in diameter. Wrap in plastic wrap and refrigerate until firm enough to slice. It may be refrigerated overnight or frozen for up to a month.
Put a rack in the center of the oven and preheat the oven to 325 degrees. Line two baking sheets with Silpats or parchment paper. If the logs have been frozen, let them stand at room temperature until soft enough to cut without crumbling.
Mix the granulated sugar and cinnamon in a small bowl. Cut each log into 16 to 18 slices about 3/8 to 1/2 inch thick. Coat both sides of each slice with the cinnamon and sugar and place on the baking sheets.
Bake, in two batches, for about 20 minutes, or until light golden. Transfer to racks to cool. Store in an airtight container.
I doubled the recipe, which resulted in 52 cookies (instead of 64-ish, which would have been the true doubled amount). The logs I made were about 1 and 1/2 inches to 1 and 3/4 inches in diameter (which attributed to fewer cookies) because 1 inch diameter cookies seemed too small to me. I also ended up putting in about 2 and 1/3 cups flour (instead of 2 cups for a doubled recipe) because the dough wasn’t coming together and was sticky still at 2 cups of flour.
I prepared the single recipe amount of the cinnamon sugar coating and that was plenty for a doubled recipe. I even had about one-third of it left over. For the single recipe, you could probably get away with preparing half of the suggested coating amount.