How to Make It
Butter a 15- x 10-inch rimmed baking sheet. Melt 1 1/4 cups butter in a large heavy saucepan over medium; stir in granulated sugar, brown sugar, water, molasses, instant espresso, cinnamon, and salt. Cook, stirring constantly, until a candy thermometer just registers 290°F, about 20 to 25 minutes. Remove pan from heat, and stir in 1 1/2 cups of the chopped toasted almonds. Quickly pour mixture into prepared pan, and spread into an even layer, covering bottom of pan. Immediately sprinkle chocolate chips over top; let stand 5 minutes to melt. Spread chocolate in an even layer over toffee, using an offset spatula. Sprinkle evenly with remaining 1/2 cup chopped almonds. Let stand 5 minutes, and if desired, sprinkle with sea salt. Cover and chill until firm, about 30 minutes.
Break toffee into about 18 pieces. Store in an airtight container in refrigerator up to 7 days. Serve cold or at room temperature.