Preheat the oven. Preheat the oven to 350°F (175°C) and line the muffin pans with cupcake liners. This recipe yields 24 very full cupcakes or 26 smaller ones.
Mix the wet ingredients. Combine the vegetable oil and white sugar in a large mixing bowl. Then, beat well until fully combined and creamy. Next, add the sourdough starter discard and gently mix it into the batter. Add the eggs one at a time, beating well after each addition. Stir in the vanilla extract.
Add the carrots, pineapple, and raisins. Reduce your mixer speed to low and gently fold in the grated carrots, drained pineapple, and golden raisins until evenly distributed throughout the batter.
Prepare the dry ingredients. In a separate large bowl, whisk together the flour, cinnamon, allspice, salt, and baking soda. Gradually add the dry ingredients to the wet ingredients 1 cup at a time, mixing gently after each addition until just combined. Be careful not to overmix.
Fill and bake. Divide the batter evenly among the prepared cupcake liners. Fill to about ⅔ full. Bake for 25 minutes, or until the tops are lightly bouncy when pressed.
Cool the cupcakes. Cool in the pan for a few minutes before moving them to a wire rack to cool completely before frosting.