Peanut Blossoms

• 1/2 cup shortening
• 1/2 cup creamy peanut butter
• 1/2 cup light brown sugar
• 3/4 cup white sugar, divided
• 1 egg
• 2 tablespoons milk
• 1 teaspoon vanilla extract
• 1-3/4 cups all-purpose flour
• 1 teaspoon baking soda
• 1/2 teaspoon salt
• Hershey Kisses©