Prep the rhubarb: Trim both ends of the rhubarb (removing any leaves), slicing the stalks in half lengthwise and then again crosswise. Toss with ⅓ cup of the sugar and a pinch of the cardamom, then set aside to macerate while you prepare the rest of the cake.

Make the streusel: using a food processor or pastry cutter, pulse the flour, almond meal, sugars, salt, and spices a few times until combined, then add the butter and pulse (or cut) a few more times until the mixture is fine, crumbly and well-combined. Stir in the sliced almonds, and pinch small handfuls of the mixture together to form small lumpy, crumbly blobs. Set aside.

Make the cake: Preheat the oven to 350 F and grease/parchment-line a 9 x 13-inch baking dish. In a large mixing bowl, whisk together the flour, baking soda, baking powder, salt, cinnamon and the remaining sugar and cardamom until thoroughly combined. In another bowl or large measuring cup, whisk the sour cream, oil, eggs, vanilla and almond extract until smooth. Form a well in the flour mixture and pour in the sour cream mixture. Stir until fully incorporated, but don’t overmix. Scrape the thick batter into the prepared baking dish, smoothing the top as best you can. Lay the macerated rhubarb on top in a single layer, then sprinkle the streusel mixture over the top. Bake until a toothpick inserted in the center of the cake comes out without wet batter, about 55 to 65 minutes. Allow the cake to cool in the pan on a wire cooling rack for at least 30 minutes, then either continue to cool completely or serve warm.