Add yeast to warm water, stir, and set aside.
In a large bowl, mix flour, butter, sugar, and salt, either by hand or in a food processor. If a food processor, pulse about 10-12 times until the mix is the consistency of fine crumbs.
Stir the eggs into the yeast mixture. Then, add in the sour cream and vanilla and add the entire mixture into the flour mixture. Pulse repeatedly until the dough begins to come together.
You can turn out the dough onto a floured surface and knead for five minutes, or place the very wet dough into a mixer and knead on lower speed with a dough hook for five minutes.
If not on a floured surface yet, turn out the dough. Cut in half (or in four if making smaller almond rolls) and cover all but the dough you are working with in plastic wrap.
On floured parchment paper, roll out the dough until roughly a 12" square, or 6" if making four in total. Try to make sure the thickness is as even as possible throughout.
Spread half of the almond filling (or one quarter of the filling if making four rolls) onto the dough evenly. Sprinkle ¼ cup of the ground almonds on top (or ⅛ if making four), making sure to evenly distribute.
Very gently, start rolling up the dough like a roulade. The dough is very soft, since we did not refrigerate it yet, so be ginger and allow the parchment paper to do the work as you roll.
Bring the roll back to the center of the paper and tuck in both ends, slightly compressing the roll and slide the parchment paper onto a baking sheet. Repeat process with the other parts of the dough, whether making two or four.
Cover baking sheets/rolls with towels or plastic and let proof for one and a half hours. I like to place in an oven after heating to 200 degrees and shutting off, and leaving the oven door slightly ajar.
Preheat oven to 350 degrees. Bake rolls for 40-45 minutes if making two rolls, and 30 minutes if making four rolls, or until golden brown.
Immediately move to wire rack to cool.