Preheat oven to 350ºF. While oven is still preheating, spread almonds on a baking sheet and toast until golden brown - keep an eye to make sure they don't burn.
Beat butter with sugars, egg yolks and vanilla. Stir in flour. Dump onto a large, parchment-lined baking sheet and use your palms to spread it out to a rough rectangle of 1/4" thickness (it doesn't have to be a perfect shape). Lightly dampen your hands as needed if dough gets too sticky. Bake about 15 minutes, until deep golden brown (it'll smell like toffee!). Let cool about 10 minutes on baking sheet.
Meanwhile, place chocolate in a large microwave-safe measuring cup or bowl. Microwave at 50% power for 2 minutes, then let stand for 2 minutes and stir to finish melting. (Alternatively, melt in a heat-proof bowl over a saucepan of simmering water.) Spread chocolate evenly over cookie base, then top with almonds and sprinkle with salt. Let cool in pan until chocolate is completely set (up to 12 hours), then cut or break into pieces.