In a mixing bowl, cream butter and sugar until fluffy. Beat in eggs, one at a time. Add sour cream and vanilla; mix well. Combine the flour, baking powder, baking soda, salt and cinnamon; stir into creamed mixture just until moistened. Fold in strawberries and ½ cup nuts. Pour into a greased 8 x 4 x 2-inch loaf pan. Sprinkle with remaining nuts. Bake at 350 degrees for 65 to 70 minutes or until a toothpick inserted near the center comes out clean. Cool for 10 minutes; remove from pan to a wire rack to cool completely.