Lemon poppy seed old fashioned donuts

Steps

1. DOUGH: In a small bowl, sift together flour, baking powder, salt, and nutmeg
2. In a stand mixer, with the paddle attachment, add sugar and lemon zest. Rub together briefly with your fingertips to release the zest oils into the sugar. Add soft butter and mix for 1 minute, on low speed, until sandy. Add egg yolks and mix for 1 minute, on medium speed, until combined. Scrape down bowl as needed.
3. Add dry flour mixture to wet egg mixture in three separate additions, alternating with the sour cream (start and end with the dry ingredients). Mix each addition, on low speed, just until combined. Transfer the sticky dough to a clean bowl and cover with plastic wrap. Chill in the fridge for at least 2 hours or overnight.
4. Set the temp of a deep fryer to 325F (165C) or fit a large pot with a candy thermometer and oil (~2in deep). Line a large baking sheet with parchment paper and set a wire cooling wrack onto the baking sheet. Prepare lemon poppy seed glaze and set aside until ready to use.
5. On a well floured work surface, roll out the chilled dough to 1/2in thickness. Cut out rounds and each of their centers (3 1/4in round cutter and 1 1/8in round cutter). Dip cutters into flour between each cut. Gently re-roll dough scraps and repeat. Shake off excess flour from rounds and place on a parchment lined baking sheet. Transfer to the fridge and keep cool until fryer is at the proper temp.
6. Carefully add two dough rounds to the hot oil. Once the donuts float, about 10-15 seconds, gently flip them over. Fry for 2 mins, until cracked and light golden, then flip over and fry the other side for 2 mins. Again, flip over and fry for 1 min. Flip once more and fry for another min. Transfer to the prepared cooling wrack. Immediately, coat each donut with glaze, flip over and glaze each of their tops. Sprinkle generously with poppy seeds. Repeat frying (allowing oil to reheat to 325F between each addition) and glazing process until all donuts are coated. Scrape up the glaze drippings that fall onto the parchment paper and reuse to finish coating donuts if needed.
7. Serve donuts warm or allow them to cool, store, and enjoy the next day. Store leftover donuts, in an airtight container, at room temp.
8. GLAZE: In a bowl, whisk together powdered sugar, light corn syrup, salt, vanilla, and lemon juice until smooth. Any leftover glaze may be stored in an airtight container for up to 1 week.