Chocolate-Dipped Shortbread

Line 2 rimless baking sheets with parchment paper. Place oven rack in centre of oven. Heat to 300°F (150°C).

In mixing bowl, whisk flour with cornstarch. In large mixing bowl and using wooden spoon, beat butter with sugar until fluffy. Stir in vanilla.

Stir in flour mixture, half at a time, to make smooth dough with no streaks.

On lightly floured work surface and using hands, roll dough into two 9-inch (23 cm) logs; cut each log into 9 pieces. Roll each piece into ball. Place, 2 inches (5 cm) apart, on prepared baking sheets.

Bake, 1 sheet at a time, in centre of oven until bottoms are golden brown, 30 to 35 minutes. Wearing oven mitts, transfer baking sheets to rack. Let cool for 2 minutes. Using metal spatula, transfer cookies to rack and let cool completely.

Line rimmed baking sheet with parchment paper; set aside. Pour enough water into small saucepan to come 1 inch (2.5 cm) up side. Heat on stove over medium heat until hot but not boiling. Remove from heat.

Place chocolate chips and oil in heatproof bowl. Wearing oven mitts, place bowl over hot water; stir until chocolate is melted and smooth. (Be careful not to get any water in chocolate or it will clump.) Move bowl to work surface.

Dip cookies, 1 at a time, halfway into chocolate, shaking gently over bowl to remove excess. Dip into desired decorations. Set on prepared baking sheet. Refrigerate until chocolate is firm and shiny, about 30 minutes.