Chocolate chip cookies and other cookies can spread out when there's not enough flour in the mixture.
If there isn't enough flour to hold that melted fat, the chocolate chip cookies will over-spread.
Spoon and level that flour or, better yet, weigh your flour.
If your chocolate chip cookies are still spreading, add an extra 2 Tablespoons of flour to the cookie dough.
Baking soda is best when you want to make chewy cookies while baking powder is better for when you wan to make light and airy cookies.
Baking soda reacts to the acid in a recipe, while baking powder reacts to liquid and heat.
Baking soda changes the texture of baked goods by causing a batter or dough to spread, while baking powder produces light, fluffy texture.
When baking cookies you should bake the cookies on the middle rack.
When baking cookies you should heat from the bottom but bake the cookies on the center rack.
Place a thermometer inside the oven to check that the temperature is accurate--home ovens can be off by 50 degrees or more, making a huge difference for cookies.
350 degrees Fahrenheit is a good temp for chocolate chip cookies for example.
Generally, cookies are baked in a moderate oven — 350 degrees F (175 degrees C) — for 8 to 12 minutes, depending on the size of the cookie.
For chewy cookies, allow them to cool on the baking sheet for 3 to 5 minutes before transferring to a cooling rack.
For more even baking, position oven rack at the center of the oven and bake one sheet of cookies at a time.
If you prefer to bake two sheets, space racks so oven is divided into thirds and switch cookie sheets top to bottom and back to front halfway through baking.
Putting raw dough on cookie sheets still warm from the oven can cause them to begin spreading, leading to burnt edges.
Always allow baking sheets to cool completely before adding more batches.
To expedite cooling, rinse warm—but not hot—sheet under cold tap water.