No need to preheat the oven yet, this dough needs to chill!
Place the flour, oats, strawberries, salt, bicarb/baking soda and cinnamon into a medium sized bowl and stir until all the strawberry pieces are coated in flour. Leave to one side.
Place butter and sugars into a large bowl, or the bowl of your stand mixer and beat until light and fluffy; around 2-3 minutes on medium-high speed.
Add in the eggs and vanilla extract, scraping down the sides of the bowl as necessary, and mix on med-high speed until well incorporated.
Tip in your flour and strawberry mixture and mix on low until a soft dough forms.
Transfer to a medium sized bowl, cover with cling film and then place in the fridge for at least 2 hours, 6 if possible.
Once chilled, preheat the oven to 180C/350F and line 2 baking trays with silicone mats/Silpat/grease proof paper.
Using a 1.5tbsp cookie scoop, place dough balls 2 inches apart and then press them down ever so slightly with your palm to stop them rolling away.
Place in the oven for 10-12 minutes, until risen, golden and they are firm to the touch on the outer edges, but still a little soft in the middle.
Leave to cool on the trays completely and then store in an airtight container, at room temperature, for 3 days.