In a large bowl cream butter and sugar. Beat in egg. Beat in oil, vanilla, butter flavoring. Combine the flour cornstarch, baking powder and salt. Stir into creamed mixture.

Roll into 1-inch balls. In a small bowl lightly whip egg whites. Dip each bowl halfway into egg white and then into pecans. Place nut side up 1-inch apart on baking sheets covered with parchment paper. Make an thumb indentation in to the center of each cookie. Bake at 350 degrees for 8-10 minutes or until edges are lightly browned. Re-press thumbprint if needed while still warm. Remove to wire racks. Fill each cookie with 1/4 teaspoon of cranberry sauce and let cool. Drizzle with melted white chocolate (optional) and allow to set.