I use toffee filling often when baking. It is perfect in pies, candies, and various pastries. It is however hard to find in supermarkets and when you do find it, it tastes to more like caramel then toffee. I like to make my own, which is a little time consuming, but very easy.
Full time 3 1/2 hours
Makes 14 oz toffee
1 (14 oz.) can sweetened condensed milk
Water, lots of water
Remove label from around the outside of can.
Place can in a deep sauce pot.
Fill pot with water to cover the whole can.
Boil pot over medium-high heat for 3 hours. Watch pot carefully to make sure there is always water in it.
I set a timer and come back every 20-30 minutes to top it off with water. This allows me to do what I need to and still make the toffee.
Once 3 hours has past, using tongs remove can from pot carefully and place on a heat resistant surface.
Allow to rest 15 minutes.
Carefully open can and use toffee.
If you are not using it right away, pour toffee from pan and into an air tight container and store in refrigerator for up to five days.