Preheat the oven to 425°F (220°C).
In a medium bowl, stir together the ground almonds, all-purpose flour, and room-temperature butter until smooth and evenly combined.
Add the salt, cayenne pepper, lemon zest, lemon juice, and Worcestershire sauce to the almond mixture and mix well to form a spreadable almond butter.
Lightly pound each chicken breast to an even thickness.
Spread the almond butter mixture generously over the top of each chicken breast, then sprinkle the slivered or sliced almonds evenly over the coated chicken.
Place the prepared chicken breasts in a buttered baking dish and bake in the preheated oven for about 15 minutes, or until the chicken is cooked through and the almonds are golden brown.
Remove from the oven and serve immediately.