Preparation Sauté sausage in large nonstick skillet over medium heat until brown and cooked through, breaking up with back of fork, about 6 minutes. Using slotted spoon, transfer sausage to bowl; cool. Butter 13x9x2-inch glass baking dish. Whisk eggs, milk, salt, and pepper in medium bowl. Arrange half of bread in bottom of prepared dish with bases of triangles facing in same direction. Scatter half of sausage, then half of plums over bread. Arrange remaining bread in dish with triangles facing in opposite direction. Scatter remaining sausage and plums over. Pour milk mixture over; press on bread to submerge. Cover; chill overnight. Position rack in center of oven and preheat to 350°F. Place strata on rimmed baking sheet. Bake uncovered until strata is puffed and golden and knife inserted into center comes out clean, about 1 hour. Let stand 10 minutes. Cut strata into squares and serve with maple syrup.
Preparation Sauté sausage in large nonstick skillet over medium heat until brown and cooked through, breaking up with back of fork, about 6 minutes. Using slotted spoon, transfer sausage to bowl; cool. Butter 13x9x2-inch glass baking dish. Whisk eggs, milk, salt, and pepper in medium bowl. Arrange half of bread in bottom of prepared dish with bases of triangles facing in same direction. Scatter half of sausage, then half of plums over bread. Arrange remaining bread in dish with triangles facing in opposite direction. Scatter remaining sausage and plums over. Pour milk mixture over; press on bread to submerge. Cover; chill overnight. Position rack in center of oven and preheat to 350°F. Place strata on rimmed baking sheet. Bake uncovered until strata is puffed and golden and knife inserted into center comes out clean, about 1 hour. Let stand 10 minutes. Cut strata into squares and serve with maple syrup.