Crust: Mix graham cracker crumbs and remaining ingredients in a small bowl to blend. Press mixture on bottom and up sides of one 9" metal or glass pie dish. Chill until crust is firm, about 30 minutes.
Ganache: Place chocolate and butter in a large bowl. Bring cream, coffee, and 2 tablespoons water to a boil in a small saucepan. Remove from heat; cover and let steep for 5 minutes.
Strain cream mixture through a fine mesh sieve into bowl with chocolate and butter; discard coffee grounds. Stir until melted and ganache is smooth. Pour into chilled crust; smooth top. Chill until set, about 1 hour.
Meringue: Using an electric mixer with clean dry beaters on medium speed, beat egg whites in a medium bowl until light and frothy. Add sugar in 4 additions, beating for 1 minute after each addition. Continue beating egg whites until stiff and glossy.
Spoon meringue over coffee ganache, swirl decoratively with a spatula or the back of a spoon. Using a kitchen torch, if desired, toast meringue until golden brown in spots. Pie can be made 8 hours ahead. Keep chilled.