Strawberry streusel bars recipe - easy homemade dessert

Ingredients

• Base
• 1 c. (2 sticks) butter softened
• 1 c. granulated sugar
• 1 tsp. vanilla extract
• 1 lg. egg
• 2 c. all-purpose flour
• 1 (10 oz.) jar strawberry preserves
• Streusel
• 1 c. all-purpose flour
• ¼ c. cold butter
• ¼ c. granulated sugar