Crack the eggs into a separate bowl. Put the flour, baking powder and salt together in another bowl and combine with a whisk.
Place the sugar in the bowl of a stand mixer and grate the blood orange zest directly into the bowl. Use your fingers to rub the zest and sugar together. This method better releases the oils and flavor of the orange zest into the batter.
For this cake you will need 1 cup in total of blood orange juice - 1/4 cup for the cake, 1/2 cup for the soaking syrup and about 1/4 cup for the glaze. After zesting your oranges juice them until you 1 cup of juice.
Add the butter and vanilla to the sugar orange zest mixture. Beat the butter, sugar , vanilla and orange zest on medium-high speed until the butter and sugar are fluffy, about 8 minutes.
Scrape down the bowl. Add eggs one at a time on low speed and then increase to medium until each egg is well incorporated. Stop the mixer after adding the first 3 eggs and scrape the bowl from the bottom to ensure the ingredients are well mixed. Add the remaining 2 eggs and scrape the down the after adding the last egg.
Add 1/4 cup of blood orange juice and mix on medium until well combined.
Add one-third of the dry ingredients and mix on low speed until well combined, but do not over mix. Add one-half of the sour cream and mix on medium speed until well combined. Add half of the remaining dry ingredients, then the rest of the sour cream. Add the remaining the dry ingredients and mix until just combined. Scrape the bottom of the bowl and mix on low speed for about 30 seconds.
Scoop the batter into the prepared bundt pan. Bake for 55-65 minutes until a skewer inserted in the center comes out clean.