Preheat oven to 300°F. Place the butter, brown sugar and white sugar in an electric mixer fitted with a paddle attachment. Cream them together for 2 minutes. Add the egg, lemon juice and zest. In a small mixing bowl, sift the flour, salt, baking soda and baking powder together. Add the flour mixture to the butter mixture in three batches. Using a spatula, fold in the white chocolate chips.
Drop the cookies on a parchment lined cookie sheet using a 1 ounce scoop. Flatten the dough slightly. Bake for 20 minutes or until the edges of the cookies are light brown. Cool completely.
While first batch of cookies is baking, prepare the glaze. Combine powdered sugar, lemon juice and almond extract and stir into a smooth glaze. Drizzle over cooled cookies and allow to set for about 20 min.