Rhubarb Compote
In a small saucepan, combine rhubarb, sugar, orange zest and juice. Bring to a low boil stirring frequently. Simmer until rhubarb is macerated and compote has reduced down, about 30 minutes. Compote will thicken as it cools.
Rhubarb Almond Cake
Preheat oven to 350°. Butter tart pan and sprinkle evenly with sugar. Slice rhubarb in half lengthwise and set aside 8 of pieces for the top of the cake; chop remaining rhubarb into ½” pieces. Set aside.
Sift together flour, almond meal, baking powder, cardamom, and salt.
Place 1 cup butter and ¾ cup sugar in bowl of standing mixer. Beat on medium until light and fluffy, about 4 minutes. Add eggs, one at a time, making sure it’s fully incorporated before adding the next. Beat until mixture is pale and fluffy, about 4 minutes. Scrape down batter.
Reduce speed to low and gradually add dry ingredients. Add yogurt and zest. Beat for another 1 minute. Fold in chopped rhubarb with spatula. Scrape batter into prepared pan. Smooth batter and arrange reserved rhubarb over top; sprinkle with remaining 3 Tbsp. sugar.
Batter will seem really full, but will contain itself during the bake.
Place tart pan on a large rimmed baking sheet and bake for 70 minutes, rotating once. Check cake doneness by inserting toothpick. Cake is done when toothpick comes out clean. Transfer to a wire rack and cool completely. Serve with vanilla bean whipped cream and rhubarb compote.