Melt butter in a large saucepan. Add sugar, Karo, and water.
Cook at medium heat, stirring occasionally until the thermometer reaches hard-crack (300°).
Quickly stir in the coarsely chopped almonds and spread the mix on the greased jellyroll pan.
Sprinkle half the chocolate chips over the hot candy. Wait a minute for them to soften, then use a spatula to spread the chocolate evenly over the surface. Dust finely chopped almonds over the chocolate.
Allow to cool completely. Turn the candy over onto waxed paper.
Melt the remaining chocolate and spread it over toffee. Sprinkle with the remaining almonds.
Allow to cool. Break apart into serving sized pieces.