I made a big batch of Badam Katli a few months back for a puja in the local temple. The 2 kinds in the picture above are both Badam Katli - the darker one is made with Trader Joe's Almond meal which had almond skin and the lighter one is made with Bob's Red Mill brand Almond meal. Both taste pretty similar and use the same methodology.
Here's how I made these Badam Katli:
1 packet of Almond Meal (4 cups)
3 cups confectioner's sugar
1.5 cups dry milk pwd
1 to 2 tsp cardamom pwd per taste
Take the Almond meal in a large mixing bowl.
Boil some water in a pan. Place another pan on this such that it stays firmly over the larger pan with the water. Add the sugar and milk pwd to this top pan. Mix together well for 5 mins. The idea is to slightly warm the sugar + milk pwd.
Add the sugar + milk pwd to the almond meal. Add the cardamom pwd.
Mix well using a little pressure till it all comes together in a dough-like form. You can use a few drops of milk if the mixture is too dry and not coming together. But I think the oil from the almond meal is sufficient to bind it all together.
Roll this dough into a circle with a rolling pin. Use parchment paper under the dough while rolling to make it easier to roll. Cut into desired shapes. Store in the fridge. Can be served cold or at room temperature.
To cut them into evenly shaped diamonds, I use my 2 fingers as a measure. First I cut the rolled dough with a pizza cutter vertically into strips (each 2 finger-wide). Then I cut it diagonally again using the 2 finger measure. This gave me pretty consistent shaped katlis, except the end pieces which were happily gobbled up by my daughter and me.