In all formulas, it is essential that all ingredients be scaled/measured as accurately as possible and that they be at room temperature. Refrigerated items can be safely left out at room temperature for up to 2 hours to come to temperature.
Measure ingredients, prepare pans and being preheating oven before beginning mixing.
Creaming Method with OilStir together flour and other dry ingredients, excluding salt; set aside.
In a small bowl, whisk together the flaxseed or commercial egg replacer and water; if using yogurt, leave aside; if using eggs, break into small bowl and whisk with a fork just to break yolks, set aside.
With a paddle attachment, beat together fat, sugars and salt in a large mixing bowl at medium-high speed until lighter in color and finer in texture, about 4-8 minutes; taste the mixture for doneness – it should be just a mite grainy and the sugar should crunch only slightly. If melted chocolate is being used, it may be added during this stage.
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Reduce mixer speed to low and add any liquid flavorings (extracts). With mixer running, slowly add flax/replacer mixture/yogurt/eggs. Mix until just combined. Stop mixer and scrape down bowl.
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With mixer on low speed, add flour mixture in three batches, waiting until each is just combined before adding the next. Scrape bowl in between additions.
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If using, stir in mix-ins in one or two batches, according to recipe.
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Chill, if necessary, portion, bake and cool.