Line a rimmed baking sheet with a nonstick baking mat. In a small saucepan, combine sugar and 1/4 cup water over medium-high; cook, swirling occasionally, until sugar is completely dissolved and mixture is medium amber in color. Remove from heat; immediately stir in pecans. Pour onto prepared sheet; let cool completely.
Transfer candied pecans to a cutting board and coarsely chop. (To separate candied pecan pieces from any "dust," place chopped candied pecans in a clean mesh sieve and sift.) Candied pecans may be stored in an airtight container up to 2 weeks, or in freezer up to 1 month.