Cacher is the code snippet organizer for pro developers

<?php
/* DON'T copy the first line (above) if your functions.php already has it. 
 * ---------------------------------------------------------------------- */

function my_et_theme_image_sizes( $sizes ) {
	$sizes['350x350'] = 'my-et-pb-post-main-image-fullwidth';
	
	return $sizes;
}
add_filter( 'et_theme_image_sizes', 'my_et_theme_image_sizes' );


function my_et_pb_index_blog_image_size( $size ) {
	return 375;
}
add_filter( 'et_pb_index_blog_image_width', 'my_et_pb_index_blog_image_size' );
add_filter( 'et_pb_index_blog_image_height', 'my_et_pb_index_blog_image_size' );

/* You must regenerate your thumbnails after adding the above code to your child theme.
 * The following plugin is the best tool for the job: 
 * https://wordpress.org/plugins/force-regenerate-thumbnails/
 */