Directions

1. Preheat oven to 325 degrees F (165 degrees C). Wash 8 (pint) straight sided, wide mouth canning jars in hot soapy water. Rinse well, dry and let them come to room temperature. Grease insides of jar well.
2. In a medium bowl, sift flour, baking soda, baking powder and salt. Set aside.
3. In a large bowl, cream butter with half of the butter until fluffy. Add eggs and remaining sugar and beat in. Add vanilla and applesauce and combine.
4. Add the flour mixture in three increments, mixing well after each addition.
5. Pour 1 cup of batter into each jar and carefully remove any batter from the rims.
6. Bake at 325 degrees F (165 degrees C) for 40 minutes.
7. While cakes are baking, sterilize lids and rings by boiling them in a saucepan of water. Keep them in the hot water until ready to use.
8. When the cakes have finished baking, remove jars from oven. Make sure jar rims are clean. (If they're not, jars will not seal correctly). While jars are still hot, place lids on jars, and screw rings on tightly. Jars will seal as they cool. Place the jars on the counter and listen for them to "ping" as they seal. If you miss the "ping", wait until they are completely cool and press on the top of the lid. If it doesn't move at all, it's sealed.
9. Unsealed jars should be stored in the refrigerator and eaten within 2 weeks. Sealed jars may be placed in a freezer.