Beat butter at medium speed with an electric mixer until creamy; gradually add sugar, beating well. Stir together espresso powder and water. Add to butter mixture, stirring well.
Combine flour and salt; gradually add to butter mixture, beating at low speed until blended. Stir in toffee bits. Cover and chill dough 30 minutes.
Roll dough to 1/2" thickness on a lightly floured surface. Cut with a 2 1/2" round cutter or Christmas cookie cutter. Place 2" apart on ungreased baking sheets.
Bake at 275° for 50 minutes. Cool 2 minutes on baking sheets. Remove to wire racks to cool.
Note: If you can't find almond toffee bits in the supermarket, substitute 1/2 cup finely crushed Skor candy bars or crushed Werther's Original candies.