Pour 2 cups of water into a microwave-safe cup or bowl. I always use a liquid measuring cup.
Microwave it for 2 – 3 minutes until boiling. Remove water from microwave.
Place butter pieces into a heat-proof bowl or plate, then place into the microwave.
Close the microwave to trap hot air inside. Butter will soften in 10 minutes
Baking soda. A base that interacts with the acid in your recipe (buttermilk, brown sugar, cream of tartar, etc.) You don’t want to use too much because too much leaves a metallic taste. I generally use 1/4 teaspoon of baking soda per 1 cup of flour in a recipe. Expiration Date!
Baking powder: Consists of baking soda, cream of tartar, and sometimes cornstarch. Starts to leven when it gets wet (combining dry ingredients with wet). Levens again when heated. Some recipes call for both because sometimes you need more leavening than you have acid available in the recipe. Expiration Date
Cake Flour. Measure 1 cup of all-purpose flour. Remove 2 Tablespoons. Mix in 2 Tablespoons of cornstarch. This equals 1 cup of cake flour.