Preheat a cast-iron griddle or skillet over low heat. Preheat the oven to 300˚ F. Combine the cream cheese, jam and almonds in a bowl and beat with a mixer on medium-high speed until combined.
Slice the challah into 2-inch-thick slices. With a paring knife, make a 1/2-inch horizontal slit in the bottom crust of each slice to form a deep pocket. Using a butter knife, fill each slice with some of the cream cheese mixture. Set aside.
Whisk the eggs, milk, brown sugar and almond extract in a baking dish. Dip the stuffed challah slices in the egg mixture to fully coat, about 30 seconds per side.
Increase the griddle heat to medium. Add the butter and let it melt, then add the stuffed challah to the griddle. Cook until golden brown, about 4 minutes per side. Transfer to a rack set on a baking sheet and keep warm in the oven until ready to serve. Garnish with almonds and serve with maple syrup.