Preheat the oven to 200℃ and line a baking tray/sheet with baking paper/parchment paper and set aside.
Boil/steam/microwave your potato in salted water until it is tender - I microwave mine in a large glass bowl with the potato covered in water on high for about 25 mins (see notes regarding salt).
650 g potatoes (see my notes), ¼ teaspoon cooking salt
Lay your bacon rashers out long ways, and trim the wider parts so you have a long piece of bacon roughly 3 cm (1¼") wide the whole length of the rasher (see my notes).
4 rashers streaky bacon
Once your potato is tender, mash it well until you have no lumps then add melted butter, garlic powder, shallots/scallions, sour cream, 25 g parmesan cheese and milk (gradually), mixing well to combine - don't over mix (see notes).
2 tablespoon salted butter, 2 tablespoon sour cream, 4 spring onions (scallions/green onions), ¼ teaspoon garlic powder, 30 g grated fresh parmesan cheese, 1 tablespoon milk
Once combined, take about ⅔ cup of mashed potato mixture and form it into a rough ball. Place the potato ball on to work surface and flatten slightly with your fingers.
Take one rasher of bacon and wrap in loosely around the slightly flattened ball - then flatten the ball to fill out into the ring of bacon and secure the bacon with a toothpick and repeat until you have 4 cakes - try not to pack them down too much - the potato will sit roughly even with the top of the bacon.
4 toothpicks
Roughen the top of the cakes gently using a fork - this helps them crisp a little on top.
Place panko crumbs on a shallow plate, and sit the potato cakes one by one into the panko to lightly coat the bottom with crumbs, then place the potato cakes onto the prepared baking tray (there will be panko left over).
1½ tablespoon panko bread crumbs
Mix the remaining panko crumbs with the remaining 5 g of grated parmesan cheese, and sprinkle this breadcrumb mixture evenly over the top of the potato cakes
30 g grated fresh parmesan cheese, 1½ tablespoon panko bread crumbs
Bake for 20 mins or until lightly browned on top, then grill/broil for a further 3 mins for some extra crunch.