Preheat your oven to 350ºF and press your unbaked pie crust in a 9-inch pan. (You can use an unbaked store bought crust, if you like.)
In a food processor fitted with an "S" blade (or in a high speed blender), combine the dates, maple syrup, flax seeds, 1/2 cup of the pecans, and the salt. Process until the dates are broken down and you have a relatively smooth batter.
Pour 3/4 cup of the pecan halves into the pie crust and spread them out evenly. Pour the batter over the pecans and use a spatula to smooth it evenly. Top the pecan pie filling with the remaining 1/4 cup of pecans-- I like to crush them between my fingers and sprinkle them over the top so that the little pieces are evenly distributed.
Place the pie in the oven to bake at 350ºF for 45 minutes. When it's done baking the top should look drier and the edges of the filling will be firm to a light touch.
Allow the pie to cool completely, for at least 2 hours. You can put it in the fridge to speed the process, if you'd like to. Slice the pie and serve chilled or at room temperature.
Leftover pie should be covered and can be stored on the counter for up to 3 days, or in the fridge for up to a week.