To make the sauce, in a small saucepan melt the butter over medium heat. Whisk in the walnut oil, honey and brown sugar. Cook, stirring continuously until the sugar is dissolved, about 3 minutes. Stir in the milk, 1 tablespoon at a time, and then cook, stirring continuously until the sauce thickens slightly, about 3 minutes. Remove from the heat and stir in the raisins. Set aside and keep warm.
Peel the bananas, and then cut each crosswise into 3 sections. Cut each section in half lengthwise. Lightly coat a large nonstick frying pan with the canola oil and place over medium-high heat. Add the bananas and saute until they begin to brown, 3 to 4 minutes. Transfer to a plate and keep warm.
Add the rum to the pan, bring to a boil and deglaze the pan, stirring with a wooden spoon to scrape up any browned bits from the bottom of the pan. Cook until reduced by half, about 30 to 45 seconds. Return the bananas to the pan to rewarm.
To serve, divide the bananas among individual bowls or plates. Drizzle with the warm sauce and serve immediately.