Pre-heat oven to 375°F and line 12 muffin tins. Heat milk, chai, and butter in a small saucepan over low-medium heat. Bring to a simmer and remove from heat. Set aside and let cool. Before using, strain out chai from milk (or remove tea bags).
Stir together flour, baking powder, salt, and cinnamon.
In a separate bowl, whisk together eggs, sugar, brown sugar, and vanilla. Slowly whisk the milk and tea mixture. Stir wet ingredients into the dry until just combined. Do not over mix. Fold in raspberries.
Using your hands, create the crumble by mixing together the remaining butter, flour, brown sugar, and cinnamon until combined. Fill muffin tins almost to the top (about 3/4 full) with the batter. Top with crumble. Bake for 17-19 minutes until golden brown and the muffins spring back when lightly touched. Be sure not to over bake.