Preheat oven to 350F (180C). Line a baking sheet with parchment paper or lightly oil. In a bowl, stir cookie mix with vegetable oil, water and egg until a soft dough forms.
For large cookies, drop tablespoonfuls (15 mL) of dough about 2 inches (5 cm) apart on sheet. Bake in centre of preheated oven until just set, 10 to 12 minutes. Cool cookies completely. For mini cookies, drop teaspoonfuls (5 mL) of dough onto sheet. Bake until set, 8 to 10 minutes.
To make spiderweb, squeeze icing in a small hexagonal star in centre of cookie, then a larger one around it, leaving space between. Make sure points of stars line up. Squeeze a dot of icing in centre of small star, then drag icing toward a point on large star. Repeat until web is complete. Cookies will keep well, at room temperature, up to 3 days.
Nutrition (per serving)
These cookies are fun for the whole family. The scary part is how easy they are to make. They start with a mix and store-bought icing. So bake away!