It's in the Leavener

• Banana bread relies on baking soda or baking powder to make it rise. Measure the leavener accurately because too much can cause your banana bread to rise rapidly and then sink. You typically need about 1/4 teaspoon baking soda or 1 teaspoon baking powder for each 1 cup of flour. Sift the leavener thoroughly into the flour before adding it to the wet ingredients. Store baking powder and baking soda in a cool, dry pantry and replace it every six months to one year. Baking powder, especially, begins to lose its effectiveness after about six months, and a stale leavener may cause a loaf that's dense, hard or sunken in the middle.

The Toothpick Test

• Banana bread typically needs at least 45 to 55 minutes to cook. Shorter cooking times may cause the top to sink. Although you can't fix a loaf that's already sunk, you'll find success next time. Knowing when the bread's done can be tricky. If your bread sinks after you take it out of the oven, it probably wasn't done in the middle. Your banana bread may look golden-brown on top, but don't buy it. You've got to check the center of the loaf. Set the oven temperature at 350 degrees Fahrenheit, and place the pan in the center of the oven. Don't bake more than two loaves at a time, or they may not bake evenly. Set the timer for five to 10 minutes before you think the loaf will be done. Insert a toothpick in the center of the bread. It should come out clean, with just a few moist crumbs. If it comes out wet, add more time.

Check the Batter

• Banana bread may sink if the flour to moisture ratio is off -- which can easily happen when you're dealing with bananas. A typical recipes call for two or three ripe bananas, but bananas can vary widely in how much moisture they have. Very ripe bananas have a lot of moisture, while less ripe bananas are much drier. The batter should be about the same consistency as cake or muffin batter, stiffer than pancake batter, but looser than cookie dough. Add 1 to 2 tablespoons of flour if your batter is too thin or if the bananas were moister than usual.

Cut It Out

• The banana bread emerged from the oven golden-brown and beautifully risen. Yet, when you cut into it, it sinks and becomes soggy and mushy. The problem in this case is simply that the bread needs to cool more before you cut it. Cool the bread in the pan for 10 to 15 minutes before turning it out onto a cooling rack. Allow it to cool for at least two hours before you slice it. For even better flavor, wrap the banana bread in plastic wrap and store it at room temperature overnight. In the morning, it will be moist, yet firm, and easy to slice.