Preheat oven to 400 degrees. Grease bottom only of six 6 oz. custard cups (or eight large muffin cups, 3 x 1 1/4 inch). Beat egg in large bowl with fork; stir in milk and oil. Stir in remaining ingredients except for fruit and topping. Stir just until flour is moistened, then fold in the fruit. Fill cups 3/4 full and sprinkle tops with streusel topping.
Bake until golden brown; custard cup - 20 to 25 minutes, muffin cups - 15 to 20 minutes. Cool on rack for 5 minutes. Remove from cups, cool completely.
3 tbsp. flour
2 tbsp. sugar
2 tbsp. butter
Mixed until crumbly.