Brownie mixes are simple to use, but require exact measurements for success. Add too much oil or water and you'll likely have a sticky, gloppy mess. Read the directions carefully before you begin. A common mistake is to transpose the water and oil quantities. Follow the directions for high altitude baking found on the side of the box if you live 3,000 feet or more above sea level.
When brownies have too much water, they don't brown properly and they have a mushy, soggy quality. They may not hold together, falling apart when handled, or they may seem oily. Properly prepared brownie batter has a smooth, thick consistency. Ir the batter is thin or watery, you've added too much water. Homemade brownies usually don't contain water, relying on eggs and oil or butter for moisture. Brownie mixes require 1/4 to 1/2 cup water, depending on the brand.
If the batter seems runny, add a few tablespoons flour to thicken it. Add the flour one tablespoon at a time, stirring after each addition, because too much flour will toughen and dry the brownies. Don't add more than 4 tablespoons flour. If the batter is still watery, your best option is probably to start over with a new batch of brownies.
Although you may be able to fudge measurements and ingredients when cooking meats and main dishes, baking requires exact measurements for success. Read the directions carefully. Use a glass measuring cup when measuring liquids, and set it on the counter after you've filled it to steady the cup and accurately read it. Add the water only after you are certain the amount is correct.
Dress up ordinary brownies from a mix with a few simple ingredients. Place half the brownie mix in the pan. Spread a thin layer of raspberry jam over the brownie mix and then add the remaining brownie mix. Bake as directed. Drizzle melted chocolate or white chocolate over the cooled brownies. Add chocolate chips or toffee bits to the batter.