Gradually add flour and mix until combined thoroughly. Set aside.
(Can be done with hands or with a mixer.)
(Dough can be refrigerated if desired)
Beat eggs and brown sugar together.
Add vanilla and chopped nut of your choice.
Separate the dough into small pieces and press onto tart pan to create a small cup. A non stick pan is preferable. You can improvise also by using a cupcake tray, if you don't have any tart pans.
Spoon nut mixture into each tart. Do not over fill and remember to stir the nut mixture every time you spoon because the nuts have a tendency to float to the top. You want each tart to have a fair amount of nuts.
Bake for roughly 30 minutes or until the edges are golden brown. There will also be "cracks" in the tarts as well to indicate if they have cooked or not. The oven must be at 350 degrees. *must be hot.
Once cooled, remove from the pans and sprinkle with powdered sugar as a garnish.