Heat oven to 375 degrees. In a medium bowl, whisk starch, gum, salt, baking powder, pudding; set aside. In a small bowl, beat yolk, cream, and vanilla with fork until combined; set aside.

In standing mixer, cream butter and sugar at medium-high speed until light and fluffy, 3 to 4 minutes. Scrape down bowl with rubber spatula. With mixer running at medium speed, add yolk/cream mixture and beat until incorporated, about 30 seconds. Scrape down bowl. With mixer running at low speed, add starch mixture until the dough is formed, about 1 to 2 minutes. ( If too dry add an extra tablespoon of heavy cream. )

In a well greased 9 x 13 pan, press the dough into an even layer. Bake until light golden brown, about 20 to 25 minutes. Place the base in the fridge for 15 minutes to cool.

Meanwhile, prepare the crumb topping: Place baking mix, tapioca, xanthan gum, baking powder, salt, brown sugar, sugar and pudding mix in food processor work bowl fitted with steel blade. Pulse briefly to combine. Add chilled butter and pulse until mixture moves from dry sand-like appearance with large lumps of butter to a coarse cornmeal texture, about five 4-second bursts. Continue to pulse until larger crumbs start to form and the mix starts to resemble a crumb topping, with chunks being about ½ inch pieces. Refrigerate mixture while preparing fruit.

Rough chop the fresh raspberries and place in a bowl with jam. Add in lemon juice and stir until combined.

Add raspberry filling evenly to the cooled base. Sprinkle crumble on top. Bake for 35 to 40 minutes.

Allow to cool completely before cutting. Add powdered sugar on top if desired.