1 cup butter (no substitutions)
2 1/2 cups packed brown sugar
1 cup light-colored corn syrup
One 14-oz. can sweetened condensed milk
1 tsp. vanilla
Line a 9x9-inch baking pan with nonstick foil or buttered foil, allowing edges to hang over sides of pan; set aside.
In a large microwave-safe bowl combine butter, brown sugar, corn syrup, and condensed milk; cover loosely with parchment paper. Microwave on 100% power
(high) for 4 or 5 minutes* or until butter starts to melt. Whisk to combine mixture. Microwave on high for 4 or 5 minutes* more. Whisk well. Microwave an additional 4 or 5 minutes*. Whisk gently. Add vanilla. (Note: Bowl may get hot as mixture cooks; use hot pads to handle.)
Pour caramel mixture into the prepared pan. Chill for 1 to 1 1/2 hours or until just firm. Using foil, lift block of caramel from the pan. Use a buttered knife to cut into 1-inch squares.
*I used a 9x13 pan to get smaller caramels to dip in dark chocolate. After dipping, I sprinkled a little sea salt on top of the chocolate.
One batch of caramels cut into "petite" squares made over 200! I found it easier to work with the caramel "slab" when I kept it in the freezer. I'd cut a strip, cut into squares, dip about 20 caramels in chocolate, put them in the freezer to firm up, then put them in candy papers, and repeat.