Preheat your oven to 350F.
In one bowl, whisk together the oat flour, baking soda, and salt. In a separate bowl, combine the almond butter, maple syrup, eggs and vanilla extract and whisk until smooth.
Gradually fold the dry ingredients into the wet until well combined.
Then warm up your milk and add the instant coffee, this creates a concentrated "coffee syrup" for flavoring the cake. Add this to the batter and mix.
Pour into an 8x8' baking sheet lined with parchment paper. Bake at 350F for 20-25 minutes.
Once the cake is out of the oven, let it cool for at least 20 minutes before sifting powdered sugar on top as a topping.
Store in an airtight container for up to 5 days.