In a mixing bowl add rhubarb and liquid from jar, sour cream, sugar, vegetable oil, vanilla, baking powder, egg and salt. Mix
Fold in flour being careful not to mix too much
Pour batter into a parchment lined loaf pan
Bake for about 60-65 minutes*, or until firm when lightly touched on top, and a toothpick inserted near the center comes out without wet batter on it (wet crumbs are fine.) If the bread seems to be browning too quickly towards the end of baking, lay a loose piece of foil over the top.
Let cool for 15 minutes in the pan, then use the parchment paper to remove the cake to a cooling rack to cool completely. Note: if you aren't using parchment paper, let the cake cool in the pan.