In a 2-qt heavy bottomed saucepan, combine the butter, sugar, corn syrup, vanilla, and salt. Cook over medium heat until the butter is melted and the sugar has dissolved, stirring constantly. The mixture will be bubbling by this point.
When everything is melted, increase the heat to medium-high and cook while continuously stirring until the mixture reaches 300°F (hard-crack stage), about 9 to 15 minutes. The toffee will be golden-brown, but it's best to check with a digital thermometer. If the candy appears to separate (with a layer of melted butter on top) stir vigorously to make it come back together again.
Once the toffee has come to temperature, immediately pour it onto the prepared pan. Use a large offset spatula to spread it out evenly as soon as possible. You don't need to go to the edges of the pan, although you can. Allow to cool for 2 to 3 minutes.
Sprinkle the chocolate chips over the surface of the hot toffee and let sit for 5 minutes or until the chocolate appears glossy. Spread evenly over the surface with the same large offset spatula. Dust the top of the melted chocolate with the almond meal.
Allow the toffee to cool completely in the pan, about 1 to 2 hours.
Once the toffee is cool and the chocolate set, start breaking the toffee into irregular shards with your hands or a butter knife. Store the candy at room temperature in an airtight container.
For a crunchier nut topping, replace the almond meal with ¼ cup toasted chopped almonds. You can also use chopped pecans or walnuts, whatever you prefer.Some recipes call for putting 1 cup of whole toasted almonds on the baking pan before adding the toffee. It's a personal preference of course, but I'd focus on the toffee this time (no judgements!).Experienced candy makers can tell by the toffee's golden-brown color if it's ready, but I prefer the precision of using a digital thermometer (or a candy thermometer clipped to the side of the pan) to make sure the candy reaches hard-crack stage (at least 300°F).Use a good heavy-bottomed saucepan to avoid having your toffee burn.This recipe makes about 1¼ lb of toffee, and each piece weights about ⅔ oz (20g).