• Preheat oven to 375°. Line a muffin pan with paper baking cups.
• In a large bowl, whisk together the sifted flour, sugar, baking powder and salt. Set aside. In a medium bowl, whisk the eggs, melted butter (it should be cooled before adding), lemon and orange zest. Add the buttermilk to the egg and butter mixture, then the lemon and orange juice, then the vanilla, and whisk until thoroughly combined.
• Create a well in the middle of the dry ingredients and pour the wet ingredients into the well, then stir until just moistened. Gently fold in the candied ginger, if using. 
• Fill muffin cups evenly; they should be about 2/3 full, maybe a little more. Bake for 18-23 minutes or until golden brown and a toothpick inserted into the center of a muffin comes out clean. Cool for 10 minutes before moving muffins to a wire rack to cool completely (out of the tin). Garnish with a bit of crumbled candied ginger and/or lemon and orange zest, or drizzle with lemon orange glaze.

Lemon Orange Glaze

• In a small bowl or pourable measuring glass, whisk 1/2 cup of the sugar with the lemon juice and the blood orange juice. If mixture is too thin, keep adding confectioners sugar a little at a time, whisking until you have a thick and smooth but still pourable glaze. When muffins have completely cooled, pour glaze over the muffin tops. A squeeze bottle works great for this.