Sterilize 6 (1 pint) straight sided wide mouth canning jars, lids and rings by boiling for 10 minutes. Keep the lids and rings in the hot water until needed. Preheat oven to 325 degrees F (165 degrees C). Dry jars and let them come to room temperature. Grease insides of jar well.

In a medium bowl, sift together the flour, baking powder, soda and salt. Set aside.

In a large bowl, cream sugars and butter with electric mixer. Add eggs and mix well. Add milk and vanilla and mix well.

Add flour mixture and blend with a large spoon. Gently fold in nuts.

Place 1 cup batter into each of the greased one pint wide mouth canning jars. Wipe any batter from rim. Place jars on baking sheet. Bake at 325 degrees F (165 degrees C) for 50 minutes or until toothpick inserted deep into center of cake comes out clean.

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.

Keep in refrigerator for prolonged storage.