Step 1

In a medium saucepan gently simmer the rhubarb, sugar and pinch salt for about 25 minutes over low heat.

Step 2

Add the frozen strawberries and vanilla extract.

Step 3

Bring to a boil simmer gently for another 5 minutes before adding a thickening slurry, made by mixing together the corn starch and water.

Step 4

Simmer only for an additional minute or two, stirring constantly. Remove from heat and cool to room temperature.

Step 5

Using a food processor or a pastry blender cut cold butter into flour, brown sugar and salt until mixture resembles a coarse meal. Small pieces of butter should still be visible.

Step 6

Pour vanilla into cold water then pour over the mixture and work in by tossing with a fork until dough begins to form. Use your hands as little as possible and work the dough as little as possible.

Step 7

Divide dough into 2 balls, flatten into 2 rounds, wrap in plastic wrap and place in the refrigerator to rest for a minimum of 20 minutes.You can make your dough the previous day but make sure you take it out of the fridge for 10 minutes to warm slightly before rolling out. Since this is a a one crust pie, freeze one of the pastry rounds for later.

Step 8

Roll the dough into a 12 inch round and place in the bottom of a 10 inch pie plate. Trim and flute the edges as desired. You will need to blind bake this bottom crust before adding the filling. Blind baking is essential so that the bottom crust will not get soggy.

Step 9

To blind bake a crust simply place a piece of parchment paper over the dough and cover the bottom of the pie plate with baking weights. (Marbles, dry beans, peas, rice or barley work just as well as anything else.) Bake at 400 degrees for about 15-20 minutes. Remove baking weights and parchment and bake for an additional 5 minutes.

Step 10

Cool the pastry for about 10 minutes before adding the fruit filing.

Step 11

In a large bowl toss together the baking powder, oats, flour and brown sugar.

Step 12

Using your fingers, rub the butter thoroughly through the dry ingredients.

Step 13

Sprinkle the crumble evenly over the fruit filling. At this point, cover the outside crust of the pie with strips of aluminum foil so that the edges will not overbake but allowing the crumble to brown evenly as in the photo above.

Step 14

Bake at 375 degrees F for approximately 30 -40 minutes or until the crumble s evenly golden brown. Allow the pie to cool to room temperature before cutting and serving.