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.
Serve the fritule warm or at room temperature.
Enjoy your meal!