In a medium-sized bowl, combine the cake flour, instant yeast, baking soda, cream of tartar, and sugar. Whisk until well mixed.

In a small saucepan, gently heat the butter, oil, and water together until the butter is melted. Allow this mixture to cool to around 120°F (just hot enough that it won't burn your touch).

Create a well in your dry ingredients and pour in the melted butter mixture. Using an electric mixer, beat the mixture on medium and then high speed until the butter is fully incorporated and a dough forms.

Knead the dough by hand until it forms a soft ball. If it feels sticky, add a little more flour; if it’s too dry, sprinkle in a touch more water.

Lightly grease the bowl, cover it with plastic wrap, and let the dough rest in the fridge for at least 12 hours (up to 18 hours).

Remove the dough from the fridge and allow it to warm up at room temperature for about 15 minutes.

Preheat your oven to 400°F and prepare large baking sheets with parchment paper or grease them.

Knead the dough for a few minutes until smooth and divide it into four pieces. Roll each piece out as thin as possible.

Cut the rolled dough into 2x2 squares with a pizza cutter, placing them on the prepared baking sheets.

Use a fork to poke holes into each square and brush them lightly with water. Sprinkle generously with salt.

Bake for 8 to 10 minutes, checking closely at the 8-minute mark to avoid browning too much.

Once baked, allow them to cool on the tray.

Store in an airtight container for up to a week.