Heat the oven to 425 degrees. In a mixing bowl, stir together dry dough ingredients – flour, salt, and sugar. In a small bowl, whisk together the oils, milk and almond extract. Pour liquid mixture into the flour mixture and mix gently with a fork, just enough to dampen; do not over work it. Then, transfer the dough to an 9-inch to 11-inch tart pan (you can use a smaller one if needed) and use your hands to pat out the dough so it covers the bottom of the pan, pushing it up the sides to meet the edge. The dough should be about 1/ 8-inch thick all around.
In a bowl, combine the crumble ingredients -sugar, flour, salt, extract, and the butter. Using your fingers, pinch the butter into the dry ingredients until crumbly and the texture of tiny pebbles.
Arrange the rhubarb pieces overlapping in circle over the pastry. Sprinkle the crumble mixture over top (it will seem like a lot). Bake for 35 to 45 minutes, until pastry is golden thick bubbles begin enveloping the fruit. Cool on a rack. Serve warm or room temperature, with a dollop of creme fraiche or whipped cream.