Preheat oven to 180°C (350°F).
Prepare the shortcrust pastry by mixing 185g of flour, 95g of sugar, 1 egg, and a pinch of salt in a large bowl. Mix until the ingredients are combined, then add 95g of softened butter and knead the dough by hand or using a stand mixer until it forms a smooth ball. Wrap the dough in clingfilm and refrigerate for at least 30 minutes to chill.
While the dough chills, prepare the almond filling. In a separate bowl, combine 100g of softened butter and 100g of cane sugar. Blend the mixture with a spatula or hand mixer until it is smooth and creamy. Add 2 eggs one at a time, making sure to mix well between each addition. Once the eggs are incorporated, stir in 100g of almond flour and 1 tsp of almond extract. Mix until the filling is smooth and fully combined.
Remove the dough from the fridge and gently place into into a tart mould, pressing it into the edges and sides of the mould. Fold the edges over if needed and prick the base with a fork to prevent air bubbles.
Place half of the 500g of fresh blueberries on the base of the tart. Pour the almond filling over the blueberries, spreading it evenly. Top with the remaining blueberries.
Bake the tart in the preheated oven for 45 minutes, or until the crust is golden brown and the filling is set. Remove from the oven and allow the tart to cool completely before serving.