Add the butter, brown sugar, and vanilla and stir to combine. Continue cooking for 5 minutes.

Using an immersion blender or potato masher, mash the apples into a mixture as smooth or chunky as desired. Set applesauce aside.

Preheat the oven to 450°F.

Place two baking sheets in the oven to heat.

Peel the russet potatoes, but don't peel the Yukon gold. Cut potatoes in half lengthwise if needed to fit in the feed shoot of a food processor, or keep whole if shredding with a box grater.

Shred the potatoes, onion, and garlic in a food processor. (If shredding by hand, use the coarse holes of a box grater for russet potatoes and the small holes for the Yukon Gold and onion. Mince the garlic with a knife.)

Set a colander over a large bowl. Transfer shredded potatoes, onion, and garlic to the colander and push out as much moisture as possible. Reserve the pasty potato starch that collects in bottom of bowl.

Squeeze the lemon juice over potato mixture, discarding any seeds, and toss to coat.

Transfer half of the potato mixture to a food processor fitted with the blade attachment and process until smooth. (If the mixture was grated by hand, skip this step.)

Combine the shredded and pureed mixtures in a large bowl. Add the olive oil, eggs, baking powder, salt, and pepper and stir until well combined.

Use a spoon to collect the reserved pasty potato starch and add to potato mixture. (You can use as much as 1 tablespoon.) Mix to combine.

Carefully remove the baking sheets from oven.

Lightly coat the hot baking sheets with cooking oil spray. Use an ice cream scoop, measuring cup, or spoons to scoop 24 portions of potato mixture onto the baking sheets, spacing them about 1 1/2 inches apart. Press with a wide spatula to flatten.

Brush the latkes with the olive oil.

Bake the latkes on upper-middle and lower-middle racks of oven for 10 minutes.

Carefully flip latkes over. Continue baking until golden brown and crisp on both sides, 8-10 minutes.

Check to see that latkes are done. Remove from oven or add time as needed.

Transfer latkes to a platter and sprinkle with fresh herbs. Serve with bowls of applesauce, sour cream, and everything bagel seasoning, if desired. Store any leftover latkes in an airtight container in the refrigerator for up to 3 days, and reheat in a 350°F oven. Store any leftover applesauce in the refrigerator for up to 1 week.