Preheat oven too 350 degrees F/ 325 degrees F convection.  Oil a 9 inch cake pan.

Make the crumb topping.  In a medium bowl, stir together flour, ginger, cinnamon, almonds, and sugar until combined.  Stir in syrup and oil until clumps of various sizes form.  Set aside.

Make the cake.  In a large bowl, cream oil, vanilla, and sugar until well combined and slightly lightened in texture and color.  Beat in the eggs, one at a time.  Stir in half the flour, followed by the almond milk.  Stir in the remaining flour, baking soda, salt, and cardamom, just until the batter comes together.

Pour the batter into the prepared pan.  Top with an even layer of the rhubarb.  Drizzle the rhubarb with the maple syrup.  Sprinkle with crumb topping and bake about 1 hour until golden brown and a toothpick inserted in the center comes out clean or with a few crumbs.  Cool completely in the pan before slicing and serving.

Cake may be stored in an airtight container at room temperature for up to 4 days, or frozen, wrapped in parchment and foil, and placed in a zipper bag, for up to 3 months.  Thaw in the microwave about 1 minute.