Cream together butter and sugar until light and fluffy. Add egg and vanilla, mix well. Gradually blend in flour and salt until soft dough forms.

Wrap dough in plastic wrap and refrigerate for 30 minutes.

Roll out dough to ¼ inch thickness, ensuring evenness. Trim ragged edges.

Melt white chocolate and mix with powdered sugar until creamy. Spread over the dough.

Roll the dough into a tight log, seal edges, and refrigerate for another 30 minutes.

Preheat oven to 350°F (175°C). Slice the log into ½-inch rounds and arrange on a baking sheet.

Bake for 12-15 minutes until edges are golden brown. Cool on baking sheets before transferring to a wire rack.