Line a 15x10x1-inch baking pan with foil, extending excess over edges of pan. Set pan aside.
Butter the sides of a heavy 3-quart saucepan.
Melt the 2 cups butter in saucepan.
Add sugar, 1/3 cup water, molasses, and 1 tablespoon espresso powder.
Cook and stir over medium-high heat until mixture boils.
Clip a candy thermometer to side of pan.
Reduce heat to medium; continue boiling at a moderate steady rate, stirring frequently, until thermometer registers 290°F, soft-crack stage (about 25 minutes). Watch carefully after 280°F to prevent scorching.
Remove saucepan from heat; remove thermometer.
Stir in vanilla.
Pour candy into the prepared pan.
Let candy stand about one hour or until firm.
Use foil to lift candy out of pan.
Break candy into pieces that are about two inches in size.
Melt the three tablespoons butter in a heavy medium saucepan.
Stir in the one teaspoon espresso powder until dissolved.
Add chocolate pieces and melt over low heat, stirring often.
Place pecans in a shallow dish or on waxed paper.
Dip half of each candy piece into melted chocolate mixture, coating all sides.