1 cup sliced almonds
1 cup unsalted butter
1 cup granulated sugar
1/2 cup water
1/2 teaspoon salt
1/2 teaspoon baking soda
1 teaspoon vanilla extract
2 cups dark or semi-sweet chocolate chips
3/4 cup white chocolate chips
Heat oven to 350 degrees F.
Line a 13x9-inch baking dish with foil.
Place almonds on a cookie sheet and bake 8 minutes or until lightly toasted.
Bring butter, sugar, water and salt to a boil, in a large saucepan, over medium heat. Boil for about 10 minutes, stirring occasionally. When hot syrup turns light golden brown, stir in almonds. Continue to cook, stirring constantly, until syrup starts to turn golden brown. Quickly remove pan from heat and stir in baking soda and vanilla until combined; pour toffee into prepared baking dish.
Sprinkle chocolate chips on top of toffee and wait a few minutes for them to melt before spreading evenly. Sprinkle white chocolate chips on top, wait to melt, and swirl into chocolate. Cool completely before cutting into pieces.
To make a mint variation, sprinkle 1/2 cup crushed Thin Mint cookies on top, followed by 2 crushed candy canes.