Preheat oven to 325F and grease 2 circular 9-inch cake pans very well (if your pans are not very non-stick, line them with circles of parchment and grease the parchment paper too). You can also use 8-inch round pans but your cake layers will take a little longer to bake.
In a medium bowl, whisk together the almond flour, whey protein powder, baking powder and salt.
In a large bowl, beat butter with sweetener until light and fluffy. Beat in eggs, one at a time until well combined. Beat in vanilla extract.
Beat in half of the almond flour mixture, then beat in nut milk. Beat in the remaining almond flour mixture until well combined. Divide batter between prepared cake pans and use a knife or offset spatula to smooth the top.
Bake 18 to 20 minutes, or until golden brown around the edges and the top is just firm to the touch. Remove and let cool 10 minutes in pans, then transfer to a wire rack to cool completely.
Beat whipping cream with powdered sweetener past the "whipped cream" stage. It should not be smooth and homogenous-looking, but instead be a bit thicker and look somewhat clotted or clumpy. Do not keep beating after this or you will soon have butter.
Place one cake layer on a serving platter and spread with chia seed jam. Spread the clotted cream over top of the jam and place the second cake layer on top.