Preheat oven to 375°F (190°C). Line baking sheets with parchment paper.
In a large bowl, cream together butter, white sugar, and brown sugar until fluffy.
Beat in the egg, orange juice, and orange zest until combined.
In a separate bowl, whisk together flour, baking soda, and salt.
Gradually add dry ingredients to the wet mixture. Stir until fully incorporated.
Fold in cranberries and walnuts (if using).
Drop rounded tablespoonfuls of dough 2 inches apart onto prepared baking sheets.
Bake for 12–14 minutes or until edges are lightly golden.
Let cool on the baking sheet for 2 minutes, then transfer to a wire rack.
For the glaze: Mix powdered sugar, orange juice, and zest until smooth.
Drizzle glaze over completely cooled cookies and let set.