We've fancied up tender buttery shortbread with crunchy Skor bar toffee pieces.
, at room temperature
1 1/4 cups
Place oven rack at lowest level. Preheat oven to 300F (150C). Coarsely chop 1 chocolate bar into 1/4-inch (0.5-cm) pieces. They should measure about 1/3 cup (75 mL). Set remaining chocolate bar aside. In a medium-size mixing bowl, using an electric mixer, beat butter until smooth. Gradually beat in sugar until light and fluffy. Beat in vanilla and salt. Using a wooden spoon, stir in 1 cup (250 mL) flour just until mixed. Stir in remaining flour with chopped chocolate bar pieces just until mixed.
Scrape dough into an ungreased, 8-inch (2-L) square baking dish. Lightly flour fingers, then pat mixture into an even thickness. Using a fork, pierce dough every inch (2.5 cm). Finely chop remaining chocolate bar. Sprinkle overtop dough.
Bake on lower rack of 300F (150C) oven until edges are deep golden and centre is pale golden, from 35 to 40 minutes. Remove from oven. Immediately cut into 16 (2-inch/5-cm) squares. Cool completely in pan. Store in an airtight container in a cool place or in the refrigerator up to 2 weeks.