Preheat the oven to 350 degrees F (180 degrees C). Grease a 9x13-inch pan and set it aside.
In a large separate bowl whisk together the
All-Purpose Flour (3 1/4 cups)
Quick Cooking Oats (1 3/4 cups)
Granulated Sugar (1 1/4 cups)
Ground Cinnamon (1/2 Tbsp)
. Knead the
Unsalted Butter (1 cup)
plus 2 Tbsp into the dry ingredients until it forms streusel crumbs.
Press half the streusel mixture into the prepared pan.
Semi-Sweet Chocolate Chips (1/2 cup)
in a heatproof bowl. Heat
Espresso (1/2 cup)
until boiling and pour over the chocolate chips. Stir to smooth out the mixture.
. Beat the egg whites and
Salt (1/4 tsp)
until stiff peaks form. Sprinkle the
Granulated Sugar (3/4 cup)
over the egg whites.
Add the egg yolks,
Almond Butter (1/3 cup)
Ground Nutmeg (1 tsp)
to the espresso chocolate. Mix thoroughly. Fold in the sugared egg whites, then fold in the
Buckwheat Flour (1 1/4 cups)
Spread the mixture out on top of the streusel in the pan. Distribute the rest of the streusel on top. Place in the oven and bake for 30 minutes.
Espresso (1/4 cup)
Powdered Confectioners Sugar (1 cup)
Coffee Liqueur (2 Tbsp)
into a saucepan and cook, stirring until dissolved. Bring to a boil, then remove from heat.
Remove cake from the oven and let cool for 10 minutes before drizzling the syrup over the top.