1. Preheat oven to 350°F (180°C). Spray an 9x5-inch loaf pan with baking spray with flour. Line pan with parchment paper, letting excess extend over sides of pan. Spray again.
2. In the bowl of a stand mixer fitted with the whisk attachment, beat sugar, sour cream, eggs, and orange zest and juice at medium speed until combined, 3 to 4 minutes, stopping to scrape sides of bowl.
3. In a medium bowl, whisk together flour, baking powder, and salt. Reduce mixer speed to low. Gradually add flour mixture to sour cream mixture, beating just until combined. Add oil in a slow, steady stream, beating until combined. Pour batter into prepared pan.
4. Bake until golden brown and a wooden pick inserted in center comes out clean, 35 to 40 minutes. Let cool in pan for 5 minutes. Remove from pan, and let cool completely on a wire rack. Drizzle with Blood Orange Glaze. Garnish with blood oranges, if desired.
