Place apples, 1/2 c. water and lemon juice in a large pot. Bring to a boil. Lower heat and simmer, covered, for about 30 minutes, stirring occasionally. Simmer until apples are very soft. Remove from heat.

Press apples through a food mill, sieve, or (my personal choice) a spider skimmer. You need 5 cups of pulp, the texture of apple sauce. Set pulp aside and discard skins and anything leftover.

Place granulated sugar in an even layer in a 6 to 8 quart Dutch oven or other heavy-bottomed pot. Heat over medium-high heat until sugar starts to melt, gently shaking the pots back and forth if needed but don’t stir. When sugar starts to melt, lower heat to medium-low. Allow to cook for another 5-10 minutes, stirring frequently with a wooden spoon, until sugar is melted and golden.

Carefully, add remaining 3/4 c. water to the caramel already on the stove. Beware of mixture bubbling. Caramel will then seize up but keep cooking and stirring until caramel melts again, and is the same consistency throughout.

Add apple purée and brown sugar - again, mixture will bubble. Stir until sugar has been dissolved. Bring to a boil and allow mixture to boil for another 10 minutes, stirring frequently. (As mixture is boiling, now is a good time to start bring the water for the hot water bath to a boil.) Mixture should reduce to about 6 cups. Remove from heat and stir in butter and vanilla.

Quickly ladle into sanitized canning jars, leaving top 1/4-inch empty. Wipe rims. Put on lids and seal with bands.

Transfer jars to a pot filled with boiling water. Allow to process in boiling water for 10 minutes. If water stops boiling when adding the jars, bring to a boil again and then start 10 minute timer.

Remove jars and set on a towel-lined baking sheet or a wire rack to cool. Check to confirm jars sealed - if any did not, immediately put the jar in the fridge to use immediately.