• For the streusel, in a bowl, combine flour with pecans, granulated and brown sugars, cinnamon, and cardamom. Drizzle with butter; use a fork to evenly mix.
• For the cake, lightly oil or line a 10-inch cast-iron frying pan with parchment paper. Prepare the grill for indirect cooking. For a two-burner gas grill, light one side of the grill to medium and leave the other side off. For a three-burner grill, leave the middle off and turn on the two outer burners. Preheat to 350°F.
• In a bowl, whisk together flour, baking powder, baking soda, and salt. In a large bowl, using an electric mixer (use paddle attachment for a stand mixer), cream butter with sugar, scraping down sides, about 3-4 min. Beat in egg, then sour cream and vanilla. Add flour mixture; beat on low speed, occasionally scraping down sides, just until mixed. Batter will be thick. Spoon half into pan; smooth top. Sprinkle with half of the streusel. Drop remaining batter, by spoonfuls, overtop. Smooth batter (it’s okay if there are still bare spots). Sprinkle with remaining streusel.
• Place pan on the unlit side or middle of the grill. Close lid; bake for 38-45 min or until a toothpick inserted in the centre comes out clean. Let cool on wire rack at least 15 minutes before eating. Or, cool completely and then glaze.
• For the glaze, whisk sugar with lemon juice and salt. Drizzle over cooled cake.

Make ahead, save time: prep ingredients so you wake up, preheat the grill, assemble the cake, and start the coffee

• Freeze streusel for up to 5 days or refrigerate overnight.
• Measure dry ingredients for the cake. Measure butter right into the mixing bowl. Cover bowls and leave both in a cool place (on the counter) overnight.
• Squeeze lemon juice for the glaze; store in the fridge overnight.