Preheat your oven to 350 degrees F.

Prepare a 1 lb loaf pan (~ 9 x 5 x 3): either grease it, or line with parchment paper.

Combine the 1 tbsp cinnamon and 1/3 cup sugar, and set aside.

Using a mixer cream the butter and sugar together until smooth.

Add the eggs and mix well.

In a separate bowl, whisk together the flour, baking powder, baking soda and salt.

In a separate measuring cup stir together the buttermilk and vanilla.

Add the flour mixture, alternating with the buttermilk, to the butter mixture. Combine.

Stir in the chopped strawberries and rhubarb.

Add 1/2 of the batter to the loaf pan, then sprinkle on 1/2 of the cinnamon/sugar mix. Then using a fork, stir it a little into the batter.

Add the rest of the batter and sprinkle on the rest of the cinnamon/sugar mix. Stir again, just a little.

Bake for ~ 60 - 75 minutes, or until a toothpick inserted into the centre comes out clean.