01 - Preheat oven to 375°F. Line a 12-cup muffin tin with paper liners or lightly grease each cavity.
02 - In a large mixing bowl, whisk together the flour, granulated sugar, cinnamon, ginger, nutmeg, allspice, baking powder, baking soda, and salt until evenly blended.
03 - In a separate medium bowl, beat the eggs thoroughly. Add the milk, vegetable oil or melted butter, and vanilla extract, whisking to fully combine.
04 - Pour the wet mixture into the dry ingredients. Stir gently until just combined; avoid overmixing for optimal texture.
05 - Gently fold in crystallized ginger and raisins or chopped nuts if desired.
06 - Distribute batter evenly into the prepared muffin tin, filling each well about two-thirds full.
07 - Bake on the center rack for 18 to 22 minutes, or until a toothpick inserted into the center of a muffin comes out clean.
08 - Allow muffins to cool in the pan for 5 minutes, then transfer to a wire rack to cool completely before serving.