Pre heat oven to 200 c fan forced / 390 f and line a baking tray/sheet with baking paper/parchment paper & set aside
Boil/steam/microwave your potato in salted water until it is tender - I microwave mine in a large pyrex/glass bowl with the potato covered in water on high for about 25 mins (see notes regarding salt)
Lay your bacon rashers out long ways, and trim the wider parts so you have a long piece of bacon roughly 3 cm or 1 ¼ " wide the whole length of the rasher (see notes)
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 & milk mixing well to combine - don't over mix (see notes)
Once combined, take about ⅔ cup of mashed potato mixture & form a rough ball. Place potato ball on to work surface and flatten just 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 & 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
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 potato cakes onto prepared baking tray - there will be panko left over
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
Bake for 20 mins or until lightly browned on top, then grill/broil for a further 3 mins for some extra crunch