Preheat oven to 350°F. Grease and flour mini Bundt cake pan.
In the bowl of a stand mixer fitted with the whisk attachment, beat eggs and sugars at medium high speed until light and fluffy, about 4 minutes.
In the meantime, in a measuring cup with spout mix the olive oil, buttermilk, and almond extract.
In a medium bowl, whisk together the flour, baking powder, and salt.
Reduce the speed of the mixer to low and gradually add the buttermilk-oil mixture in a slow steady stream. Continue mixing until well combined.
With the mixer at low speed, slowly add the flour mixture and mix until combined.
Remove bowl from the mixer and fold into the batter the chopped rosemary and grapefruit pieces. Divide the batter evenly onto the Bundt cake pans. Bake for 20-25 minutes until golden brown and a toothpick inserted in the cake comes out clean.
Allow the cakes to cool in the pan for 5 minutes and then carefully remove from pan; let the cakes cool completely on a cooling rack.