Add ingredients to a mixer with a dough hook attachment and mix for 3 minutes on low until a dough ball forms.

Increase mixer speed to high and continue to mix for another 6 minutes to develop the gluten. The dough should look smooth and should be clearing the bowl at this point.

Transfer dough to a bowl and round it into a ball, tucking the dough up under itself to create tension. See video @1:43 for demo.

Cover the bowl with a lid or plastic wrap and allow it to sit at room temperature to ferment for 60 minutes.

After 60 minutes, the dough should have risen by about 30-40% (if it hasn't risen that much, continue to ferment).

Flip dough onto a floured work surface and flour the top of the dough. Use a flat hand or rolling pin to degas the dough a bit then roll it into a rough square shape that's around 11"/28cm across.

Use a knife or dough scraper to cut off each edge so you're left with a more precise square shape that's about 9"/24cm. Then cut this cleaned up square into 9 3"x3"/8x8cm squares.

Place the donut squares on a parchment lined sheet tray to proof, covered, for 60-70 minutes at room temperature. I usually just use a second sheet tray to cover.

They should have doubled in size when they're ready to fry (see below for filling and frying process).

Add berries, sugar, lemon juice, and vinegar to a heavy bottomed pot over medium-high heat, stir to dissolve the sugar and bring to a simmer. Cook for 10 minutes, stirring frequently, until raspberries are softened and have lost most of their liquid.

Press about half of the cooked raspberry mixture through a fine mesh strainer to remove some of the seeds, returning the passed pulp to the original pot and discarding the seeds.

Return the pot to the stove over medium high and bring to a simmer, then whisk in 60g of fruit pectin and continue to cook until the mixture reaches 220F/105C.

Once it hits this temp, transfer jelly into a shallow bowl or two to cool. Then chill in the fridge.

Add oil to a large heavy bottomed pot and heat to 340F/170C.

Fry donuts in batches, allowing enough space around donuts to not get stuck together. I fry in 3 batches of 3 for my 6.75qt dutch oven.

After 90 seconds, use a long spoon or spider strainer to flip donuts to the second size and continue to fry for 90 more seconds until golden all over.

Transfer donuts to a wire rack to drain.

While still warm, gently blot top and bottom of each donut into sugar to lightly coat.

Transfer jelly to a piping bag and cut off the tip of the bag to create an opening.

Insert the handle of a wooden spoon into one side of each donut, moving the spoon handle back and forth inside to open up a cavity for the jelly while keeping the insertion hole as small as possible.

Insert the tip of the piping bag into the hole and squeeze in about 3 Tbsp or 45g into the cavity that you made.