As I was making your cookie recipe this morning, I remembered I had a recipe for some with balsamic vinegar in them. I went thru my files and there it was and I had written on it, "Good Taste", so I must have made them before! (I don't remember making them, guess it's smart of me to write on recipes I make!)
Thought you might be interested:

BUTTER PECAN COOKIES (with Balsamic Vinegar)
1 stick butter, softened
1 cup packed light brown sugar
1 large egg
2 Tablespoons Balsamic vinegar
1 1/4 cups flour
1/2 teaspoon baking soda
1/4 teaspoon salt
3/4 cup pecans, coarsely chopped
Preheat oven to 375 degrees F. Spray two cookie sheets with nonstick cooking spray. Using a mixer or food processor with metal blade, combine butter and brown sugar until creamy. Add egg and vinegar and mix until well blended. Add flour, soda and salt. Mix on low speed with mixer or pulse food processor until well blended. Stir in pecans. Drop by Tablespooons 2 inches apart onto prepared cookie sheets. Bake for 8 minutes. They will be soft but will firm up as they cool. Immediately remove cookies to racks to cool. Store airtight for several days. Cookies may be frozen.Makes 3 dozen.