Drain the tuna, ensuring you reserve the oil from the can.
In a mixing bowl, combine the sifted flour with baking powder and a pinch of salt. Make a well in the center of the dry ingredients.
Crack the eggs into the well and mix with a whisk until you achieve a thick, smooth batter.
Add the crème fraîche and 2 tablespoons of the reserved olive oil from the tuna can, and whisk vigorously.
Fold in the crumbled tuna, olives, and pepper, using a spatula to gently lift and incorporate them into the batter.
Preheat your oven to 350°F (180°C).
Grease and flour a loaf pan, removing any excess flour.
Pour the batter into the prepared pan, smoothing the top, and bake for 40 to 45 minutes. Check the cake's doneness with a knife; it should come out clean.
Allow the cake to cool slightly before removing it from the pan and slicing it. Serve immediately.