Heat a skillet or griddle to medium-high heat, then add the butter and melt.
To make the French toast batter, whisk the egg, milk and vanilla together in a shallow bowl until well blended. Take the two split pieces of cinnamon roll and dip the interior sides of the roll into the batter.
Place the interior sides of the roll onto the heated, buttered skillet or griddle. Cook until golden brown, then flip over onto the sugary, glazed sides until crisp. Remove from the heat and top with fresh fruit and whipped cream.