In a large bowl, whisk together the flour, sugar, baking powder, and salt.
In another bowl, mix the milk, eggs, brandy (or milk/water), vanilla extract, and lemon zest.
Gradually add the wet ingredients to the dry ingredients, stirring until just combined.
Fold in the raisins or currants and chopped walnuts if using.
In a deep pot or frying pan, heat about 2 inches of vegetable oil to 350°F (175°C).
Drop spoonfuls of dough into the hot oil, making sure not to overcrowd the pot.
Fry the fritule until golden brown and cooked through, about 2-3 minutes per side.
Use a slotted spoon to transfer the fritule to a plate lined with paper towels to drain excess oil.
In a small bowl, mix the granulated sugar and ground cinnamon.
While still warm, roll the fritule in the cinnamon sugar mixture to coat.
Enjoy your meal!