Wash and chop berries. Toss them with 1 cup of sugar and the vanilla beans/seeds and place in a large jar or bowl.
Allow the berries to macerate for at least 2-3 hours and up to 72 hours.
When you're ready to make the jam, prepare three half pint jars.
Pour macerated strawberries into a large pot and add the remaining cup of sugar.
Bring to a boil and cook until the jam reaches 220 degrees, stirring very regularly.
Add the lemon zest and juice in the final 5 minutes of cooking.
Once the jam has reached 220 degrees, remove the pan from the heat.
Pour jam into your prepared jars.
Wipe rims, apply lids and rings and process in your canner for 10 minutes (normally I'd admonish you not to start your timer until the water has returned to a boil. However, as long as your water is quite hot when the jars go into the canner, the time it will take to return to boiling should be minimal).
When time is up, remove jars from canner and let them cool on a towel-lined counter top.
When jars are cool enough to handle, remove rings and check seals.
If any jars are not sealed, store them in the fridge and use them first.
Store sealed jars in a cool, dark place.