Make the syrup: Heat the syrup and both halves of the vanilla bean in a small saucepan over medium-low heat. Just before the mixture comes to a simmer, remove from the heat, stir in the berries and set aside for at least 30 minutes to let the flavors meld. Remove the vanilla bean before serving.
Make the pancakes: Preheat the oven to 200 degrees F. Whisk the flour, cornmeal, granulated sugar, baking powder, salt and nutmeg in large bowl. In a separate bowl, whisk the buttermilk, eggs and oil. Stir the wet ingredients into the dry until just blended. Leaving a few lumps will result in fluffier pancakes.
Heat a large nonstick skillet or griddle over medium heat. Add enough oil to grease it lightly and leave a film on the bottom of the pan.
Working in batches, ladle the batter, about 1/2 cup at a time, into the pan. Cook until the pancakes are golden brown on the bottom and bubbles start to form on top, about 3 minutes, then flip and continue cooking another 2 minutes. Repeat with the remaining batter. Put the finished pancakes on a sheet tray and let sit in the oven to stay warm as you finish. Serve topped with the berry syrup, butter and confectioners' sugar.