Add butter, brown sugar, corn syrup, salt, and condensed milk to your saucepan.
Cook on medium-high heat stirring constantly or the condensed milk will scorch.
Move quickly across the bottom of your saucepan and never lift that spoon or spatula!
Cook your caramel to the soft ball stage (235-245 degrees-- Please use a candy thermometer.)
The caramel should be a thick syrup consistency and a pretty medium color and you'll know it’s done as soon as it looks like this.
Beware, the sauce bubbles up pretty quick, so watch it closely!
Take off of the heat once you've reached the soft ball stage.
Now, move your saucepan close to your apples and toppings that have previously been prepped.