Drain pineapple reserving 3 tablespoons of juice for the frosting.
In a mixing bowl, cream together butter and brown sugar until light and fluffy.
Beat in egg, pineapple, and vanilla.
In another bowl combine flour, baking powder, baking soda, and salt and stir or whisk until thoroughly mixed.
Gradually add dry ingredients to the creamed butter and sugar.
Grease a cookie sheet with non-stick spray.
Use a cookie scoop to drop cookie dough onto the baking sheet about 2 inches apart. These cookies will spread.
Bake at 325 degrees for 17 to 20 minutes or until golden.
Transfer cookies to wire racks to cool.
Place powdered sugar, lemon zest, and 2 tablespoons pineapple juice in a small bowl. Stir to combine. Add more pineapple juice, about ½ teaspoon at a time, if needed to achieve spreading consistency.