Donuts are having a day in Delaware. Last week, Sleeping Bird Doughnuts opened at 4001 Concord Pike behind Lucky’s Coffee Shop in Brandywine Hundred. The newcomer is an offshoot of Sleeping Bird Coffee on Miller Road in Wilmington. The doughnut shop joins a bevy of businesses specializing in sweet indulgences. On nearby Marsh Road, the intriguing combo of Hill Donut Co. & Pancake House and 322 BBQ specializes …