Tips to prevent a tart crust from shrinking: Don't overwork the dough. Let the dough rest before rolling it out. Chill the rolled out tart crust before baking.
In a medium size bowl, sift together the flour, baking powder and salt.
In another bowl, cream butter, slowly add the sugar.
Add the eggs, one at a time, scraping the sides of the bowl after adding the eggs. Add the vanilla.
Slowly add the dry ingredients and milk alternately, a little at a time, until all are added, being careful not to over mix the dough.
Chill crust for one hour.
Preheat the oven to 375Fº.
On a lightly floured surface, roll out the crust. Place in a greased 11-inch tart pan. Gently shape the dough to the edges of the pan. Roll a rolling pin over the surface to remove excess dough.
Place a square piece of parchment paper on the surface. Fill with 2 boxes pie weights or dry beans.
Bake in the middle of the oven for 20 minutes. Remove the weights and parchment paper. Continue baking for 10 minutes or until lightly browned. Remove from the oven. Place on a wire rack. Cool.