Foster's Best Crumb Topping
Submitted by KitchenBarbaria... on September 10, 2012 at 7:35 am

1:2:2 ratio sugar:fat:flour

This is less sweet compared to Streusel #1 which is 1:1:1.3 ratio

Have not yet tried this but plan to - will update. This was retrieved from the Old Baking Circle (OBC) by elsa, originally attributed to MrsM and apparently posted on the OBC by Knead2Quilt. It was titled Foster's Crumb Topping - I don't know if that was a person, a bakery, a restaurant, or what, but here it is for your possible pie pleasure.

The whole Potential Pie Perfection Package:
First, the foundation of all pies, THE CRUST aka Perfect Pie Pastry Premix
Then, the center of it all, the apple pie filling aka Apple Ambrosia

And now the Parade Of Streusels
Streusel #1 - Sweet, Sweet Streusel
Streusel #2 - Foster's Best Crumb Topping
Streusel #3 - Big-Frank's Beautiful Balanced Bakery Betopping Bits, AKA Professor-Frank's Pulchritudinous Pulverulence for Proper Pastry and Pie Peaks
Yield: 1 9-inch pie

7 oz. (about 200g or 1 2/3 to 1 3/4 c) bleached AP flour
3 3/4 oz. (106 g, about 1/2c) light brown sugar
1 1/4 tsp cinnamon
8 2/3 Tablespoons unsalted butter, melted
1/16 t salt

Combine dry ingredients to blend well.

Add melted butter and stir with a fork until no more dry flour mixture remains.

Set aside for 20 minutes. DO NOT skip the rest period or the crumbs will be greasy.

This is enough for an 8 x 8 pan. (This is about the same as a 9" pie)

Because it says BLEACHED AP, I assume the originator means bleached with CHLORINE, which would perhaps imply the original recipe is either very old, say 40 or 50 years, back when most AP flour was still bleached via chlorination, or they intended the recipe for a southern style flour like White Lily.
This still doesn't match Frank's suggested ratio of 1:1:2 sugar:fat:flour ratio, but it may be the method that is the limiting factor here (e.g.--the melted butter, so you can just stir everything together). Very roughly, it's 1:2:2.