In a medium bowl, mix together the ricotta, sugar, cinnamon and vanilla using a rubber spatula. Set aside or refrigerate until ready to use.
Preheat a grill pan over medium-high heat. Brush the slices of bread on both sides with the olive oil. Grill the bread until golden brown, toasted and crunchy on the outside, about 2 minutes per side. Top each slice with a good amount of the ricotta mixture and spread evenly. Grate the chocolate over the top of the bread, fully coating each slice. Serve with a fork and knife.