Preheat oven to 190°C (375°F). Line 2 baking sheets with parchment paper. Using a hand mixer on medium speed or a wooden spoon, cream together butter and sugars until light and fluffy; beat in egg and vanilla. Mix until just combined. Set aside.
In large bowl, combine flour, coconut, oats, baking soda and salt. Mix the flour mixture to the butter mixture. Blend in pretzels, chocolate and cereal until just combined.
Drop about 30 spoonfuls of cookie dough, roughly 2 in. (5 cm) apart, onto lined baking sheets. Bake about 8 min. for chewy cookies and 10 min. for crisp ones. Cool on wire racks.