Cocoa Fudge Cookies

You can mix these incredibly simple cookies with fudge right in the pot. When freshly baked, these thin cookies have crisp edges and a chewy core. You can make it either Dutch style or with natural unsweetened cocoa powder; we chose the latter.
Preheat the oven to 350 degrees.Lightly spoon the flour into a dry measuring cup; smooth with a knife. Combine flour, baking soda, and salt; set aside. Melt the butter in a large saucepan over medium-high heat. Remove from heat; add cocoa powder and sugar (the mixture will resemble coarse sand). Add the yogurt and vanilla, stirring to combine. Add the flour mixture, stirring occasionally, until it becomes moist. Place tablespoons on a baking sheet covered with cooking spray, 2 inches apart.Bake at 350 ° C for 8-10 minutes or until almost cooked through. Cool on baking sheets for 2-3 minutes or until set. Remove the cookies from the pan; cool on wire racks.