In a large pot or skillet, heat butter, brown sugar, cinnamon, and vanilla, over medium/low heat until ingredients are incorporated.
Add apples and toss gently until everything is coated in the sugar sauce.
Cover and continue cooking over medium/low heat for about 30 minutes, stirring occasionally.
Remove from heat and serve or can. (Feel free to pack the apples and sauce separately if you want to use the liquid as a pancake or breakfast syrup. If you want to thicken, remove the apples and slowly stir in corn starch, heating for an additional 3 - 5 minutes. You'll want to serve the sauce warm as the butter may separate some in the refrigerator).