Step 1

Preheat oven to 325°. Toast 3 Tbsp. pecans on a small rimmed baking sheet, tossing halfway through, until slightly darkened in color and fragrant, 10–12 minutes. Let cool, then coarsely chop.

Step 2

Heat 4 Tbsp. unsalted butter, cut into pieces, ¼ cup (packed; 50 g) dark brown sugar, ½ tsp. ground cinnamon, and ¼ tsp. ground cardamom in a medium skillet over medium-high, whisking constantly as the mixture bubbles, until butter is melted and incorporated, about 1 minute. Add ½ tsp. vanilla extract and cook sauce, continuing to whisk, until slightly thickened, about 30 seconds.

Step 3

Arrange 2 bananas, halved lengthwise, then crosswise, cut side down, in pan and cook, shaking pan occasionally, until lightly browned, 30–60 seconds. Using tongs or a small spatula, turn bananas over and sprinkle cut sides with kosher salt. Cook, shaking pan occasionally, until bananas are browned and coated in sauce, 30–60 seconds. Remove from heat.

Step 4

Drizzle 3 Tbsp. dark rum (80–100 proof) over bananas and sauce. Using lighter, carefully ignite sauce and flambé, shaking pan occasionally, until flame goes out.

Step 5

Top with scoops of vanilla ice cream and scatter pecans over.