Preheat oven to 350 degrees F. Butter and flour 12 mini bundts.
Whisk together the flour, poppy seeds, baking soda, and salt in a medium bowl. In another medium bowl, rub the sugar and zest together. In a measuring cup combine the sour cream, milk and orange juice.
In a stand mixer fitted with the paddle, beat the butter on medium-high speed until smooth, about 1 minute. Slowly add the orange-sugar and continue beating thoroughly blended, about 3 minutes. The mixture will look a little sandy.
Add the eggs, one at a time, beating well after each. Scrape down the bowl with a rubber spatula. Drizzle in the olive oil.
Reduce the speed to low and add 1/3 of the flour. Add half the sour cream mixture. Repeat with another 1/3 flour mixture, followed by the remaining sour cream mixture and finishing with the flour, mixing just until combined. Scraping the bowl as you go.
Spoon half of the batter evenly divided into the prepared pans. Next, evenly spoon 2 teaspoons of orange marmalade over the batter in each bundt and top with the remaining batter to cover. Smooth the surface.
Bake in the center of the oven for about 18-20 minutes or until a tester comes out clean and the tops are golden brown.
Allow the bundt cakes to rest in the pan for 10 minutes, before turning out and letting cool completely on a cooling rack set over a parchment paper lined baking pan.