In a medium bowl, combine flour, brown sugar, granulated sugar, cinnamon and salt. Stir in the butter with a fork until just crumbly. Set aside.
In the bowl of a stand mixer fitted with a paddle attachment, beat butter and sugar on medium speed until light and fluffy. Add eggs, one at a time until well blended. Add sour cream, vanilla and orange zest. Beat until smooth, scraping down the bowl when necessary.
With the mixer on low, gradually add the flour mixture reserving one tablespoon to toss the rhubarb with. Remove the bowl from the mixer, and carefully fold the rhubarb into the mixture with a rubber spatula. Spread the batter into the prepared pan, smoothing the top.
Top the batter with a sprinkling of the crumbs and then the reserved 10 thin stalks of the rhubarb. (as pictured) Top the stalks with the remaining crumb mixture, pressing down slightly.
Place loaf pan on a large baking sheet. Bake for 1 hour or until toothpick inserted in center of loaf comes out clean.
Cool in pan for 15 minutes. Release from pan and let cool on wire rack.