Cut the dairy free butter or butter into small pieces and freeze for 10-15 minutes.
In a small bowl, whisk together the egg, non dairy creamer, and the vanilla.
Preheat the oven to 400° F.
In a medium bowl, sift the cassava flour, tapioca flour, almond flour, coconut flour, baking powder and sugar together. If using unsalted butter, stir in ¼ teaspoon salt.
Put the chopped pear pieces in a ramekin or small bowl and pour the lemon juice over.
Remove the butter pieces from the refrigerator and mix into the dry ingredient bowl, combining with your hands until small pieces of butter remain.
Make a well in the dry ingredients and pour in the non dairy creamer/egg mixture. Mix with a fork and then your hands to combine and form a dough that holds together. Mix the pear pieces and lemon juice in with your hands to distribute.
Turn out onto a gluten free floured board. Press the berries into the dough as you press the dough into an 8” round about 1” thick, spacing out the berries throughout the round.
Line a 9” tart pan or pie pan with a round of parchment paper. Cut the dough into 6 - 8 pieces, keeping them in the round. Move half of the round onto the prepared baking dish, and then the other half, spacing the pieces out slightly while keeping in the round.
Brush the top of the dough with 1 tablespoon of non dairy creamer. Sprinkle 1-2 teaspoons of coarse sugar over the top.
Bake at 400° F for 16-21 minutes, until puffy and golden brown on the top bottom and edges, moving the oven rack up as needed.