Preheat the oven to 350ºF. Prepare the pan: rub the bottom and sides with butter. Line the bottom with a circle of parchment or waxed paper and then butter that. Dust the bottom and sides with flour, and knock out the excess. Set the pan aside.

Put the berries in a large bowl, toss gently with the 1 tablespoon of flour, then place them uniformly in the springform pan.

Using the same bowl, thoroughly mix together the eggs and the 1 cup of sugar—I recommend a fairly sturdy whisk. Add the olive oil, then the vanilla and orange zest, and whisk again. Set the bowl aside for a moment.

In a medium bowl, sift 2-1/4 cups of white flour (sift, then measure). Then sift in the baking powder, baking soda and the salt.

Working quickly, add a third of the flour to the oil mixture and stir. Add half the buttermilk and stir again. Continue alternating adding the flour and buttermilk until everything is incorporated.

Next, sprinkle the final 4 tablespoons of sugar onto the berries in the springform pan and gently stir. Then pour the batter over the berries, all at once—it will pour in a thick golden ribbon. Smooth the top and put the pan in the middle of the hot oven.

Bake for about an hour, until the cake is golden and a tester inserted near the center comes out clean. Cool the cake on a rack for about 15 minutes. Then run a thin knife blade around the periphery, unlock the spring and take off the pan sides. Slice off the domed top (save the sliced off part to make cake crumbs for other projects or do like me—eat it on the spot). Then flip the cake onto a plate, remove the pan bottom and (working gently) the paper, and let it cool completely. Serve.