Can I replicate the best bomboloncini?

I can sure as heck try, by looking at as many recipes that look like bread, donuts, and bomboloncini as possible, to get an idea of how to make the perfect not-quite-sweet bread product with delicious sweet filling. So that's just what I did, and this will be the first documented experiment in the feat of replicating Levain bakery's raspberry bomboloncini because, although my mid-morning snack yesterday morning was beyond satisfying, at $2.25/each, I'd like to figure out how to bring my cost down just a tad.

When I woke up this morning, I mixed the dough, went to the gym, and, when I came home, it was time to shape and fill these little gems (which my mother called "mini turtle shells" when they came out of the oven). I decided to make the first batch a white batch, because white flour has more elasticity, and it rises more easily. For this test run, I wanted to use white flour and sugar. I reasoned to myself, if this batch succeeded, the next few batches I would play with using alternative ingredients. I will say, although these are delicious and delightful in their finished state, I have a lot of work to do to make them as light and chewy as Levain's. I wonder what would happen if I filled them after baking, instead of shaping them and filling them in the same step before the second rise... If anyone has any comments of any kind, leave them below, instead of the facebook page. Let's start a dialogue: Help me make light bready donuts!

Here is the recipe I used:
2 T lukewarm water
1 package dry yeast
1/2 c heated and cooled whole milk
1 1/2 c all purpose flour
2 T sugar
pinch salt
2 T softened butter
fruit spread or smooth jam
1 T soft butter
1/4 c confectioners sugar

Pour water into bowl of electric mixer and sprinkle yeast on top. Let sit for 5 min. Add milk, sugar, flour, and salt. Mix until incorporated. Add butter, mix until dough forms, about 3-5 min. Remove dough from bowl and knead on floured surface until dough is smooth. Place in oiled bowl, cover with plastic wrap, and allow to rise 1 hr.
Prepare 2 baking sheets. Line each with parchment paper. Spread softened butter into four 5" circles on each sheet. Sprinkle confectioners sugar over each buttered circle. 
Divide dough into 8 portions. Remove first portion from bowl and keep the rest covered with plastic wrap. Have floured surface ready to work on. Divide first portion in half. Flatten each piece, from outside, in, so near the edges it's thinner than in the middle. You are aiming to make two 3" circles that are slightly thinner near the edges than in the middle. Lightly brush water around the edges of each circle. Dab (about 1/2 T) some jam on the middle of one circle. Lay other circle on top. Create a seam, with your fingers or, as in the picture above, with a fork. Then gather into a ball, and place, seam-side down, on circle on prepared baking sheet. Repeat with the rest of the dough portions.
Cover both baking sheets with plastic, loosely, and set aside, 45 min, for dough to rise again.

Bake one sheet at a time, on the middle rack of the oven, at 400, for 8 min. Remove bomboloncini to a rack (use tongs).  Dig in!