Lidey's Croissant French Toast

Place croissant halves, cut sides down, in a shallow baking dish just large enough to fit them in one layer. In a medium bowl, whisk together milk, eggs, sugar, cinnamon, nutmeg, orange zest, vanilla extract, Grand Marnier, and salt until well combined. Pour mixture over the croissant halves. Soak croissants for 10 minutes, using a spoon to ladle the custard over them halfway through. Meanwhile, in a medium bowl, toss the raspberries and strawberries with the remaining 2 teaspoons of Grand Marnier. Melt half the butter in a large sauté pan over medium-low heat. When the butter is hot, place both halves of one of the croissants, cut sides down, in the pan. Immediately sprinkle the outsides with granulated sugar and cook for 4 minutes, until the cut sides are golden brown. Using a spatula, flip the croissant halves and cook for an additional 2 to 3 minutes, until golden brown. Remove and repeat with the remaining croissant. Serve immediately with the berries, maple syrup, and whipped cream, if using.