1. Preheat your oven according to the brownie mix instructions or your homemade brownie recipe.
2. Prepare your jars by thoroughly cleaning and drying them. Ensure they are heat-safe and can withstand the baking process.
3. Lightly spray the inside of each jar with cooking spray, making sure to coat the bottom and sides.
4. Prepare the brownie mix according to the instructions on the package or your preferred homemade recipe.
5. Pour the brownie batter into the prepared jars, filling them about halfway to allow room for rising.
6. Place the jars on a baking sheet to prevent them from tipping over during the baking process.
7. Carefully transfer the baking sheet with the jars to the preheated oven.
8. Bake the brownies according to the recommended time and temperature indicated in the brownie mix instructions or your homemade recipe. Keep in mind that baking time may vary when using jars.
9. While the brownies are baking, prepare a water bath for preserving the jars. Fill a large pot or canner with water and bring it to a gentle boil.
10. Once the brownies are fully baked, remove the jars from the oven and place them on a heat-safe surface.
11. Carefully lower the jars into the simmering water bath, ensuring that the water level reaches just below the lids.
12. Process the jars in the water bath for 5 minutes, adjusting the processing time based on your altitude if necessary.
13. After the processing time is complete, carefully remove the jars from the water bath and let them cool at room temperature.
14. As the jars cool, you may hear a satisfying “ping” sound indicating that the jars have properly sealed.
15. Store the sealed jars of brownies in a cool, dry place until they are ready to be enjoyed.
