Trim crusts of bread. Spread four slices with your choice of filling; cover with remaining four slices to form sandwiches. Cut each sandwich into three pieces vertically, forming “finger sandwiches.” Beat eggs, (almond) milk, and vanilla sugar in a medium-sized bowl.

Heat oil in a large skillet. Carefully dip fingers into egg mixture, and place in skillet. Fry on all four sides, until fingers are golden brown. Remove to paper towel-lined dish to drain. Continue with remaining fingers until all are fried. Sprinkle fingers with confectioners’ sugar if desired.