Crumbled biscuity tea cake

Guests? Relax.. This cake has some "sure to find in the party" ingredients, gets put together in max 10 minutes, and in an hour you just have to wait to cool a bit.
Bonus: kids can be totally involved into the making.
Holidays are for gatherings, and cookie munching anyway. :)
Hanging around the house and not doing much will definitely bring our youngest one, and mom, looking for the next cookie to be baked.
To make things worse, I found a German pastry, cookie, cake book given a long while ago by my mom, and I decided to bake as many of them as I can and of course find appealing.
Here is one easy tea cake, more like a butter biscuit coming in form of a cookie.

Ingredients
200 g butter
200 g sugar
500 g flour
1 egg
50 g almond flour
1lemon zest
dash of vanilla extract
1 tp baking powder
100 g sourish jam, like apricot, raspberry or plum. I chose plum 'cause I love it :)

Prepare a 26 cm round cake form by lining the bottom and sides with parchment paper. Preheat the oven to 180 C, 350 F.
Mix the baking powder in the flour.
Mix the butter with the sugar until creamy. Add the egg and mix few spoons of flour. The batter becomes drier, and exchange the mixer to your bare hands to mix in lightly the rest of the flour, until a crumble like batter forms.
Divide it into two equal parts.
Add half to the bottom of the form, spread and kinda press lightly until the surface is a bit homogeneous and the jam can be spread on top. Spread the jam evenly.
Mix the almond flour to the remaining butter and leave some larger crumbles. Spread it on top of the jam.
Place the cake on the lower (or second lowest if you have 5 racks) level, and bake for 45 minutes.
Let it cool a bit on a rack, sift some powder sugar on the top, and enjoy with warm tea. Bonne appetite!