Line a rimmed baking sheet with parchment paper and grease it with melted butter.

Melt butter in a medium saucepan over medium heat.

Use a good quality, heavy-bottomed saucepan, otherwise, your toffee will not heat properly and you could easily ruin it.

When the butter is almost melted, add the sugar and salt and stir with a wooden spoon until the mixture becomes homogenous. It will take a few minutes, so be patient. Keep stirring until the sugar is absorbed into the butter and looks smooth, 5-8 minutes.

Add the slivered almonds. You can also use whole almonds instead of slivered almonds or use any other nuts that you like.

Keep stirring and cooking on low heat for another 10-15 minutes, until the mixture reaches 295-300 degrees Fahrenheit. The mixture will turn a golden, caramel color. As soon as it reaches 290, stand at attention and be ready to turn it off, because it will reach 295-300 very quickly.

Please, please get a thermometer if you’re making any kind of candy. It’s very hard to tell the perfect temperature just by looking at it. If you undercook the candy, it will be a horrid texture and will probably stick to your teeth and you just might pull out a couple fillings. If you overcook it, it will become bitter and there’s no fixing it, unless you start all over again.

Add the vanilla.

As soon as the candy is the correct temperature, pour it out onto the prepared baking sheet and quickly smooth it out. Set it aside at room temperature to cool and harden, 30 minutes to an hour.

Meanwhile, melt the chocolate over a water bath. You can use any chocolate that you like. I prefer milk chocolate, but you can use dark chocolate if that’s what you like. When the toffee has cooled, pour the melted chocolate over it’s surface and smooth it out. Sprinkle with the powdered almonds. Set aside to chill and harden. You can set it in the refrigerator to hurry up the process or just leave it at room temperature, unless your house is very hot.

Break the toffee into pieces. Store at room temperature in an airtight container.