Place chopped almonds in silicone square mold and set aside.
In a heavy-bottomed saucepan over medium-high heat, combine butter and sugar and cook until melted.
Add in vanilla and salt and, stirring constantly, bring to a boil and cook until mixture is almond-colored. 5-7 minutes.
Remove saucepan from heat and pour (or scoop) over almonds in silicon mold, then let cool. Be careful not to burn yourself while pouring.
In a microwave-safe bowl, combine chocolates and melt in 30-second increments, stirring in between, until smooth.
Pour melted chocolate over the cooled toffee, then top with ground walnuts. Let cool completely.
When ready to serve, pop toffees out of mold and enjoy!