1. In a large bowl, whisk cake mix with eggs, milk, oil, 1 tsp cinnamon, and vanilla until just combined.
2. In a small bowl, combine almond flour, brown sugar, and remaining ½ tbsp cinnamon. Stir in melted butter. Streusel mixture should be crumbly.
3. Divide half the batter into muffin makers so wells are ⅓ full (about 2 tbsp each). Sprinkle ½ tbsp streusel into each well. Top with remaining batter, then remaining streusel.
4. In two batches, microwave on high for 2 ½ min. Rest in pan for 5 min before unmolding. Or, bake in pre-heated 375° F oven for 13–15 min, or until a toothpick comes out clean. Cool before unmolding.
