In a stand mixer, beat together butter and sugar until light and fluffy. Change speed to slow and add vanilla and egg mixture to butter until just mixed. Scrape down the sides of the bowl, especially the bottom.
Add flour and mix until it begins to come together. Wrap tightly in plastic and chill for 30 minutes. When ready, roll out to ¼” thick, line pie tin and chill for 10 minutes.
Preheat oven to 325°F (convection) or 350°F (non-convection) for walnut filling.
Toast walnuts in 350° oven for 8 minutes or until they’re lightly brown and fragrant.
Mix sugar and eggs together using a whisk. Stir in maple syrup, butter, vanilla and salt.
Place toasted nuts on the bottom of the tart shell and pour mixture over the top.
Bake at 325° (or 350°, depending on your oven) for 15 to 20 minutes or until the dough is golden brown and the filling shakes. Filling should start to puff slightly.
Let tart cool down before cutting and serving. Store in an airtight container for up to three days.
