Recipes from Mexico :: Mexican Desserts
1 c. butter
1 1/2 (one and one-half) c. sugar
1/4 tsp. cream of tartar
6 oz. bittersweet (not unsweetened) or
semisweet chocolate, finely chopped
1 c. coarsely chopped pecans
Line a 9-in. square or rectangular baking pan with foil, overlapping sides. Butter foil. Melt the 1 c. butter in a heavy med. saucepan over med. heat. Add sugar and cream of tartar and stir until sugar dissolves fully and completely. Increase heat to med.-high. Brush down sides of pan with a wet pastry brush. Cook until mixture registers 310 degrees fahrenheit on a candy thermometer, stirring occasionally, about 11 mins.
Immediately pour toffee into prepared pan. Let stand 1 minute. Sprinkle and distribute with chocolate. Let stand 2 mins. to soften. Spread chocolate with the back of a spoon over toffee until melted and smooth. Sprinkle and distribute with pecans. Refrigerate until firm.
Remove toffee from pan, using foil as an aid. Break into 3-in. pieces. This can be prepared four days ahead, then chilled in an airtight container.