- Bring a large pot of water to a boil. Score an "X" on the bottom of each peach with a small knife. Immerse peaches in boiling water for 30-45 seconds, then transfer immediately to an ice bath. The skins should slip off easily when you apply gentle pressure. Remove pits and chop into ½-inch pieces. 
- In a large, heavy-bottomed pot, combine the chopped peaches, sugar, and lemon juice. Stir gently until sugar begins to dissolve. Add the vanilla bean and scraped seeds (or extract) and butter. 
- Bring the mixture to a full rolling boil over medium-high heat, stirring frequently to prevent scorching. Once boiling, reduce heat to medium and continue cooking for 35-45 minutes, stirring occasionally, until the jam reaches your desired consistency. 
- Test readiness by placing a small amount on a frozen plate—it should wrinkle when pushed with your finger after cooling for 30 seconds. 
- Remove vanilla bean (if used). Ladle hot jam into sterilized jars, leaving ¼-inch headspace. Wipe jar rims clean, apply lids and bands, and process in a boiling water bath for 10 minutes for long-term preservation.