Combine salmon and garlic in a food processor. Pulse 8-10 times or until roughly chopped. Stir in salt, pepper, onion powder, panko, Dijon and mayo.
Form the mixture into 4 patties. Refrigerate 10-20 minutes to allow them to firm up.
Cook the burgers in a splash of olive oil until they are cooked through and browned on both sides.
Whisk together all the miso glaze ingredients (a few small lumps is ok). Brush the glaze over the burgers just after you first flip them, allowing the glaze to soak in while the second side cooks.
Brush with remaining sauce just before serving. Serve with buns, cucumber slices, and sprouts. Use additional sriracha and/or mayo on the bun if desired.
Recipe by Alison's Allspice at https://www.alisonsallspice.com/miso-glazed-salmon-burgers/