Why settle for a regular jelly doughnut, when you can add a creamy peanut butter filling to the mix? These are a personal favourite.
Filling & Assembly
For the doughnuts, place the milk, yeast and ½ cup of the flour in the bowl of a mixer fitted with the hook attachment and mix on low speed until blended, and let sit for 15 minutes until foamy. Add the remaining 2 ½ cups of flour, sugar, egg yolks, melted butter, vanilla, salt and cinnamon and mix on low speed to blend, then increase speed one level and knead until the dough is smooth and elastic, about 4 minutes (the dough will be sticky). Alternatively, you can blend the ingredients by hand, then turn out onto a floured surface to knead until smooth, about 6 minutes. Place the dough into a bowl, cover with plastic wrap and leave to rise for an hour or until doubled.
To cut the doughnuts, turn the risen dough out onto a floured surface and roll to ¾ -inch thickness. Cut doughnuts using a 3-inch cutter (do not cut a hole in the centre of each). Re-roll any scraps. Cover the doughnuts with a tea towel and let rise for 30 minutes.
Preheat vegetable oil to 350ºF in a tabletop fryer, or in a deep pot over medium high heat (fill the pot with 2 inches of oil). Carefully drop in a few doughnuts, leaving enough space so that they do not touch, and cook for 4 to 5 minutes, turning halfway through cooking. Lift the doughnuts onto a cooling rack with a paper-towel lined tray underneath to drain and cool for a minute, and continue to cook the remaining doughnuts in batches. Let the doughnuts cool before filling.
For the peanut butter filling, beat the peanut butter with the 1 cup of icing sugar, vanilla and 3 Tbsp of milk until smooth, adding the additional milk if needed. Spoon this into a piping bag fitted with a small plain tip (or doughnut filling tip, if you have one). Stir the jelly to soften and spoon this into another piping bag fitted with a small plain tip. Insert the peanut butter piping bag tip deeply into each doughnut and fill until you feel a little resistance. Repeat this with the jelly. Dust the doughnuts generously with icing sugar and enjoy!